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by Robert (Bob) Fenner

Pond and stream for wildlife, const.    9/28/10
Good afternoon crew.
I'm in the early planning stages for putting in a stream with a series of small waterfalls ending into a pond. I live on the top of a mountain ridge in Virginia, and a natural looking stream and pond would really enhance both our landscape and the enjoyment of our property.
While it seems that most people try to keep wildlife away from their waterscapes, I want to build mine partly for the purpose of attracting animals.
<Ah good>
I would love nothing more than to look out of my kitchen window one morning, to find a black bear is taking a dip in the pond, or a deer is enjoying a cool drink from the stream. That being the case, my challenge is to build a water structure that can withstand hooves and claws.
<Concrete... oh, I see this below>
From reading sources on both this website, as well as others, it seems that my best choice would be to create a concrete stream and pond that is underlayed with a flexible liner.
My plan is to lay down a pond liner underlayment with a flexible pond liner placed on top. The concrete would then be added in three layers,
<Oh! Do put in some reinforcing mesh...>
with the first layer being two inches deep, the second layer would be 3 inches deep and placed on top of mesh concrete wire,
<This should go in first, over the liner, ahead of the concrete>
and the third layer would be a finishing layer of another two inches.
<Mmm, and I'd place all the concrete here in one layer... unless, for whatever reason/s, you prefer to have a "smooth coat" finish... Better to leave rough for function's, and safety's sakes though>
The pond and stream would then be coated with a waterproofing primer and sealant.
<Likely no need for these... I'd add colour to the concrete if you desire...>
Does this sound like a good plan? My goal isn't to build it as cheap as possible, but rather build the most durable and long lasting structure from the beginning. So if there anything you can suggest to be done differently or added to my plans to help accomplish this, please let me know. Also, in case the concrete does crack (which I guess do to freezing and thawing is fairly likely over time), does the fact that the flexible liner isn't being exposed to the suns rays extend it's life at all?
Is there any advantage to having two layers of flexible liners underlaying the concrete shell as opposed to just one?
<Not really>
I'd like to think the stream and the pond will out last me. Thanks.
<Do please review here:
and the linked files above... In fact, please peruse our entire Pond
And feel free to write back if you have further questions, concerns. Bob Fenner>

depth of pool. Swimming pool mod. to fish pond    6/13/10
Dear Crew,
I can't find any information about dealing with the depth of a swimming pool when converting it to a pond. My 20 by 40 foot pool is 12-13 feet deep in the deep end and 4-5 feet deep in the shallow end. Should I fill the deep end with sand, or is it too deep to be safe?
<It is not too deep, and I would definitely NOT fill the deep end, or for that matter, any of the pool with sand or gravel... a maintenance nightmare. Please read here:
and the linked files above...>
Any advice would be appreciated.
Lou Anne in Southern California
<Oh, and take a look around re joining a local Koi/water garden club here.
Bob Fenner, in San Diego>

Pond Skimmer... and more re pond UVs, construction  12/29/09
Good morning,
I'm planning to remodel a small concrete Koi pond this spring. This will be the second time around and hopefully I'll correct the mistakes I made the first time.
<Heeee! Been there, done this a few times/iterations>
The original pond had a leaking plastic liner and a water channel near the top that led to a Rubbermaid trash can into which a Rio Hyperflow pump was immersed. The output of the pump went into an Aqua UV filter and from there into another round plastic tub that had filter media cut into discs. The water just fell through and drained out a pipe screwed into the side that drained into a waterfall.
<Make shift... but all the elements there>
I dug the pond out and lined it with concrete and then used Nelsonite Pool-poxy paint.
<Ughhh! I wish I had all the money I spent on Nelson's products... that didn't work. I hope your job is holding>
I cemented a regular pool-size skimmer into the side of the pond, then to a Sta-Rite 1/8 Hp self priming pump.
<Good, inexpensive (to purchase) brand... I'd look around for better energy-efficient wise. See WWM... the Pond Section/Subweb>
From there to a Laguna Chamber filter which has the baskets for media and bioballs and then MOST of the water flows out to the waterfall but with a smaller pump inside pumping about 25% of the water through the UV filter and then back to the pond. The idea was that it the water I wanted more "dwell time" in the UV. Everything works the way I intended but it's not quite "right" either.
We're digging the pond a bit wider and quite deeper, so I'm going to use a ployurea coating over the concrete rather than epoxy paint.
<Better, but still...>
I want to
add a vortex-type settlement filter before the media filter and put the UV filter back in the main line. Should it be before the settlement chamber, between that and the media baskets or leave it as is, at the end, exposing a small amount of water for a longer time?
<I'd leave as is. The move and consequent restriction in water flow is a bad trade-off>
Last, and this is the most up in the air, I'm rethinking the wisdom of having used a pool-type skimmer.
<Do keep the front screened if you leave in place/use... troubles with fish getting in/stuck...>
The size of the leaf basket is small, the diameter of the plumbing is restrictive and thus requires the self-priming pool-style pump.
<And inefficiency>
Given the energy efficiency of today's small pond pumps, I could get substantially more flow for quite a bit less wattage from one or more submersible pumps just sitting in the bottom of a secondary cavity fed from the top of the main pond.
Your comments and suggestions please?
<I would NOT use a submersible pump unless absolutely necessary... Please read here:
and the linked files above. Bob Fenner>

Natural Pools 6/30/09
Hi Robert,
I've read with interest, your article and blog on natural swimming and am hoping you can take the time to check out our work.
<Have done so... some glitches in your coding, but I really like the gist of all... esp. the Ripple Effect plan for children's' travel>
We are doing very well in Maine but have such a short season here it's crazy!
<Brrrrr! One sis was born there... I like to be where it's warm...>
We are trying to get out to the Arizona area in the winter to keep our craft going and to expose the trade to the climate out there where rain water harvesting is most important.
<Sounds good>
Any advice we can impart about these types of pools will greatly support this effort.
Thank you, Chris Robins Nest Aquatics
<Have you been out to AZ? The contractor laws are a bit different, and I/you would have to be licensed, insured there... But all is do-able. Bob Fenner>

staining a new Gunite pond   10/9/08 Dear Crew, <Dana> I looked through your excellent site but couldn't find a reference on how to stain a new Gunite pond easily or inexpensively. <Mmm... this is almost always done by applying a "cement/plaster coat" that is colored itself... over the Gunite shell... there are "jobs" where the Gunite itself is pretty much waterproof... but not always. I have seen rebar rust through... over time, and this is very difficult to mask over after... Applying one of various "pool paints" (epoxies, "rubber", et al.) can be very expensive, not very wearing/lasting... and cementaceous materials (e.g. Thoroseal et al.) may also not be long-term successful...> My husband estimates its size at 10,000 sq. ft. <Good-sized> They installed a liner and pad, <Ah, good> did the reinforcing and sprayed on the Gunite, and it looks great except it's very light and bright and needs help to blend into the red and brown dirt we have around here, especially when the level goes down, as it does every summer. <Mmmm...> Before the pond was "improved", the yerba Buena would bloom around the edges as it dried out, and it wouldn't look so bad. <I see> We need an inexpensive option, if there is one, as the pond has come in way over budget. Can we use black mason's stain or iron sulfate? <You could... along with "biological staining" this might well "do it"> I read that the iron sulfate is cheap. <Can be, yes> We do plan to put some fish in the pond but no plants as our consultant says they will cause leaks. <?... what sort of plants? None should be able to penetrate the Gunite> We built the pond for late season landscape watering, as we have no rain for 90-120 days most summers, and the well and cistern can't do it all. So the water level will go down as we pump it out in late summer, and it would look so much better if it wasn't just pale gray. It's fairly steep, as well. <Do take care that this area is safe... fenced to prevent children, stray animals from drowning> The water will be used for swimming and to water plants, so water quality is somewhat important. <... I would like to know a bit more re the filtration to be applied here... Usually there is an either/or choice to be made whether such bodies of water will be ornamental OR swimming "holes"... there are some health issues...> We mostly need to stain the top portion that shows all the time, so we don't have to do the whole thing. <Understood> I'm hoping you have an easy answer, as this will be DIY. Also, does the surface have to be sealed after staining? <Mmm, not likely. Depending on the method used ("cement plaster coating", staining, painting/coating...) Another big expense we'd like to avoid, obviously, but not if the stain comes right off. We have to do it before the rains start and the pond fills up, which is pretty soon, here in the Northwest. Could you mention suppliers for the stain, also, if you come up with some ideas? We live in Eugene, OR, and although it's not small, it's not real big either. Thanks so much for your help. Sincerely, Dana Hansler <Well... I REALLY wish I could have suggested applying a colored shotcrete shell (roughly... with small aggregate, maybe 3/8" nominal) over the Gunite along the entire edge (when it was new) and roughly tooling this to make it look more "natural"... this would allow for a better look for sure, and make it easier for life to get in and out (do take care when it is filled... treacherously slippery)... At this juncture, I would go a Thoro product route myself. Bob Fenner>

Plexiglas windows  08/18/2008 I am a swimming pool contractor and must find a Plexiglas window to insert into the side of a Gunite pool shell before it is shot. Can you direct me to the proper website? PBJB <Mmm, have had these made, years back, but don't know of a "standard" made by a company... you need a metal (likely steel of some sort) frame fabricated that can/will accommodate the Plexi viewing panel... the flange of the construct needs to be secured twixt the rebar framing of the shell... Bob Fenner>

Re: Plexiglas windows  08/19/2008 Dear Mr. Fenner: <Joan> Thank you for your prompt reply. I was certain I would not be able to find a "ready made" Plexiglas window. I am having a problem finding someone who would custom make one. <Mmm, there are folks about... Maybe see if "Rock and Waterscapes", http://www.rockandwaterscape.com/ can be of assistance, point you to a fabricator> Thank you for the information regarding the insertion of the window. <Welcome> This is my first knowledge of your website. I must congratulate you for creating such a tremendous source of information. Joan m. Brown Pools by Joan Brown, Inc. <Perhaps you will generate one for the pool/spa, water feature industry/interest. Cheers, Bob Fenner>

Re: Plexiglas windows 8/19/08 Mr. Fenner <Just Bob please Joan> Thanks again. I wouldn't know how to go about setting up a website to answer questions. <Easy to do, I assure you> I am presently working on a project. I've been a member of the State Construction Industry Licensing Board for 8 1/2 years, Chairman for one year. I am in the process of writing a book to educate people on hiring contractors, how to protect themselves, and become familiar with the State statutes, lien laws etc. Surprising how many consumers are harmed by contractors. <Ahh, I volunteered on California's "Industry Expert Program" through the CSB for years, long ago... Do agree with you re the general state of awareness of consumers, their choosings to deal with unlicensed folks... the real costs sometimes! The shenanigans I could relate!> I'll try the website you mentioned. Joan M. Brown <Real good. BobF>

This n' That... Gunite, waterproofing ponds, surrounds...  7/18/08 I am so glad you guys are there. We had a pond Gunited 3 weeks ago, it measures 33' long 22' wide 3+' deep. Around the whole perimeter is a shelf for boulders, rocks, plants, safety shelf. <Mmmm> I do not know of another way to seal this other than plaster, <Does need to be sealed... Gunite is NOT water proof> clear to the top edge, the boulders will set down in the water about 4" on this shelf. What do I seal the top shelf with? <Likely more "cement plaster" with color/oxide...> What about clear Herco rubber? <Not if I were doing it... expensive, not really an appropriate application> After whatever I uses dries I figured mixing mortar or cement to fill in the back of the shelf, <Well... I do wish we were starting from "go" here... but as the shell is already shot out... I would cement plaster (or otherwise... see WWM re... Thoro et al. products) seal the entire basin, including the "bench", then place the rocks (I'd use bits, swatches of "old carpet" to set them on... over the plaster... and seal about these in turn... and behind them a bit, to over the real water level of the berm... I do encourage you to get/use a water level... to assure this> where the void would be, set the boulders that varies 1' to 2' boulders wide on this shelf, mortar in-between the boulders and seal this with the clear Herco? <Mmm, no... won't work, or last> I am also wondering how to leach out the lime in the plaster? <No big deal... easily done over time, or through acid-washing... again see WWM re> No hurry for fish. I have 3 sequence pumps <Ahh! Very good products> pulling water from the 3-3" bottom drains, from the pumps the water is pushed up hill 25 feet away, up 12' to the 3- 15' long 3' wide 2+ feet deep biological filters, <Nice> lave rock, white filter media, brushed, returning down the 12 tall water fall. I have u.v.s for this pond, taking into consideration this pond will be in direct sunlight 6 hours a day. <Do get, record values for pH, alkalinity, perhaps DO and RedOx... and time of day readings were taken> I am also concerned about the water heating up, I am thinking of the plaster (white) coloring <? Don't do this... it won't stay white anyway... do mix some color in with this... even something other than sharp sand... e.g. crushed rock... to make stepping into the basin less treacherous... and to promote useful growth of micro-life there> it with a tint of blue/gray but keeping it on the lighter side. <Nah... again, won't stay this lighter color for any period of time... choose "something more natural"... a brown or tan perhaps> I am also concerned about algae bloom. My initial fill of water will be from filtered water, the water running through solar salt, we live in the country our water from the well has a LOT of iron in it, my neighbor is going to fill this from their system, us being concerned about to much draw on the pump in the well. <Mmm... a bunch to state... but I'd be looking into "bio-amelioration" here... using some, likely floating and "grass" plants to remove a good deal of the ferrous, ongoing available nutrient to the algae, harvesting (removing) this periodically during the sunnier, warmer months> to keep this pond topped off, I will be using a float valve, the water will be coming from our filtered water system, the water running through solar or potassium first. I do need to get the lime out of this plaster, what do you rec for doing this? (vinegar? how much) sealing the top edge of the pond to set the boulders on and topping the pond off with our systems water? thank you very much Judy <These and many more important issues are covered in a general sense in articles, FAQs files archived here: http://wetwebmedia.com/PondSubWebIndex/Pond%20Sub%20Web.htm Learn to/use the search tool (linked on the left shared border) and/or indices. Feel free to write me re specifics. Bob Fenner>

Liner with cement installation, reading/using WWM 05/15/08 Dear Crew, I am having a hard time making my choice on how to install the liner and cement bottom of my ponds. My thought is to use diamond lathe <Mmm, no... too sharp... and expensive. See WWM re... I'd use chicken wire or stucco wire...> on top of the liner to strengthen and make the top coat go on easier. I am also not sure of the best method to cap the rim of the pond. <Mmm, see WWM again... the berm needs to be firmly seated... any cap/stone to be chemically inert or out of the water... or of favorable soluble make-up...> I have flagstone I would like to use but am uncertain of the best method of securing the liner under the quartzite flagstones. <... is posted... tie (hog-rings likely) the liner and reinforcing mesh to pencil re-bar that is in turn anchored into the ground...> I live in Maui so low temperatures are not an issue. They are two round ponds approx.11ft. diameter x 2 1/2 ft high each done in stone and concrete. Any suggestions would be greatly appreciated. Many thanks Dave <Read on my brother: http://www.wetwebmedia.com/PondSubWebIndex/Pond%20Sub%20Web.htm a hu'i hou! Bob Fenner>

Natural Freshwater Habitat... pond   2/14/08 Good Afternoon, <Yawn! AM here now> I have a question about bottom substrate for a pond I am starting in an 800 gallon contoured concrete pool. I would like to create a healthy sustainable ecosystem stocked with native fish and plants (southwest florida) in as little time as possible. I understand the need for natural bacteria and their processes and had originally hoped the bottom substrate would mostly be comprised of fallen plant matter, <Mmmm> but I don't have that much time to let nature take its course. I believe my choices are between a gravel substrate or dirt bottom and Im curious as to what you might recommend. <Actually neither...> I have a small filter with waterfall feature constantly running in the pond and I would like to keep some clarity. I realize the mud wouldn't necessarily be conducive to that and was wondering if the gravel alone would be enough in assisting with the growth on natural bacteria. Any insight you can offer would be greatly appreciated. Thanks for your help. Beth Fellini <There will/should be enough biological surface area, bacterial populations, nitrification occurring in your media associated with the filter... if not, this is the place to supply something with high surface area and some chemical properties... Please read here: http://wetwebmedia.com/PondSubWebIndex/pdfiltmedia.htm and the linked files above. Other media (gravel, leaves...) on the bottom are going to be a huge mess... and a regrettable issue to keep clean... IF you intend to make this a planted system of some sort, I strongly urge you to make/use separate containers for their media... Bob Fenner>

proper sealant... Pond viewing panel  1/26/08 Howdy folks. Hope you can direct me to an answer. I am building a small pool tank and am placing Plexiglas 36? square windows in the walls for viewing fish in the freshwater tank. The wall is concrete, but lined with granite. Should be pretty. What is best sealant to place between the Plexiglas windows and granite stone (I am using stone overlapping window instead of stainless steel frame)? Water depth is 48? total. I appreciate your input. Chris <... such devices can be installed; the panel itself secured in a race of sorts... can be of a "stainless" steel make up, the nesting compound Silastic. What thickness of acrylic were you planning? For what maximum depth? Will deform if undersized... Bob Fenner>
Re: proper sealant, pond viewing panel  1/26/08
Howdy Bob. Plan on 1 1/4" Plexiglas, placed from water surface to 36" under (a 36" tall window). <I see... I would go with a 1 1/2" thickness> The tank will be 12'long x 6' wide by 50" tall. The Plexiglas will be installed within 1" pieces of granite (kind of like a sandwich with 1" overlap of 1" granite on interior/exterior. What do you think? Chris <I'd allow for at least a 2" overlap. BobF>
Re: proper sealant, pond window  1/28/08
Thanks for advice. 2" overlap and 1 1/2" thick. Seal with Silastic. Will let you know how progresses. Thanks again. Chris <Thank you Chris. Please do send along pix of the work in progress and your finished job. Cheers, Bob Fenner>

Interior Reflecting Pool   9/4/07 To Whom It May Concern: We are constructing an interior reflecting pool for a commercial lobby, in New York City. The building owner is interested in making the pool a home for goldfish. The pool will be lined with natural slate. We have been told to avoid latex based grouts and waterproofing, so as to maintain the goldfishes' health. Is this necessary? Please advise on proper waterproofing techniques. <Latex-based grouting should be fine... as well as the slate. The biological issue of expediently cycling/removing wastes needs to be addressed in terms of fostering beneficial microbes remoted, elsewhere, and providing sufficient circulation to this system and remoted filtration. Bob Fenner> Thank you,

Re: Interior Reflecting Pool   9/4/07 Thank you Bob. We do have plans to install a pump to help circulate the water. We will review the sites notes on filtration - a great source! <Thank you Jon. Feel free to send along concerns, questions, plans for a look/see. Cheers, Bob Fenner>

Ponds, oh but of course! Const.   6/22/07 Hello Mr. Fenner, my name is Larry. First let me just say that my wife and I both enjoyed browsing through your many helpful articles. We are in the process of planning for a construction of Koi pond (about 2,400 gallons in size). <A nice project!> There were quite a few things I need clarifications on, if you're available. First is the liner to surround the concrete wall/base. what size liners do I need again? <Posted... see WWM re... needs to go over all the basin/s, up and over walls...> do I need to dig footings for the wall of the pond. <I would if this is to be a formal design... with vertical walls, sharp corners... That is, something like an English garden setting> do I build the wall first, then the base later? <Yes> We would appreciate any input you might have in the future. <Glad to co-conspire with you. Bob Fenner>

Help on building a waterfall for a subdivision I am developing 03/17/07 Robert please give me a call at 239 707XXXX.  Thank you, Mike Mckee. <I don't do calls... Please write me at Crew@WetWebMedia.com BobF>

cold weather? Pond const.   2/25/07 hello, <Hello> i <I> was just wondering if it was wise to build a cement pond if you live in the north? <Can be fine> Cleveland in particular. i like the look of cement/brick ponds but i am afraid they will crack under the weather. Scott <Might... depending on how situated, what it's made of, the shape, and how it's maintained during freezing weather... All are covered on WWM. BobF>

Pond Construction, shell   8/30/06 Robert , I am a pool and landscape contractor in the central valley of California.  We are building a pool with an all natural rock water line (no water line tile)  as this rock will be half submerged what is the best mortar mix to use in this application? <Mmm, very important that the structure surrounding the rock berm extend behind the rocks... if it's Gunite, that this be "cement" plaster coated... before the rock is placed, or shot behind the rocks to a few inches above the water line... that this berm in turn be accurately sited (water level...)>   We have applied 3 coats of Thoro seal to the notched Gunite bond beam to water proof  the Gunite. <Oh! Good> I plan to fill the large voids between the rocks with a grout mix.  Again this leaves me with the question, what's the best mortar mix to use to seal between the rocks to be water tite and to hold up in a continuous wet location? <Mmm, really... the best would be "Water Plug" by Thoro... though a good sharp sand, plastic cement based mortar (pre-mixed or not) with a bit of Acryl-mix blended in will do fine here as well... along with some oxide color...> Any help on this would be appreciated. Andy Gagnon Andy Gagnon Landscapes / Cricket Pools <There are other mixes... but having something that will "take" to the Thoroseal and be attractive, not shrink is my main concern here. Bob Fenner>

Clear waterproofing... for submersed tile in pond...  - 04/26/06 Hi crew, As always... great website and help. Straight to the point, I have a client with a strange request: Indoor pond with white tile to be kept 99.99 % free of algae (lots of brushing). The major problem is with algae growing in the grout. I have thought of using a clear waterproofing product to provide a smooth surface. Any suggestions will be greatly appreciated. Samuel Toscano <I do hope there is something... I would contact tile manufacturer rep.s here first... then the products rep.s they in turn suggest... There used to be nothing that would work well or for long for this application. Two very important notes however... To use the best frost-free tile available for the install period (we used to install Latco/Europa as our first choice here). Secondly to be careful in the EXTREME to not scratch the tile and/or whatever coating you end up applying... as this will greatly expedite algal and mineral accumulation... Bob Fenner, who sees trouble>

Building My Pond    4/20/06      Okay, I've been ALL OVER your site checking things out and getting my facts. It was extremely helpful and the best site so far! I was just wondering a few things. Here's what my pond set up comes with out of the box.      8 ft. by 13 ft. area that is 18'' deep and holds up to 1200 gallons of water. Diverter/control valve directs water to a waterfall, fountain or both. Submersible pump to run both a small fountain and a waterfall at the same time.        110V submersible pump with 1170 GPH flow rate       (1) 12 ft. x 17 ft. x .02'' royal blue PVC liner       (2) extension tubes       (3) fountain heads       PVC hose, hose clamps, diverter valve        I'm a 20yr. old female, and know nothing about ponds, but I'm pretty smart. I used some of my math (thought it would never be used) to figure what I need, pricing, etc. I'm making my pond out of pressure treated wood and I plan on getting the dimensions of 8'x13' with the 18" deep. I have it ALL figured out on paper and in mah head. <Good>        BUT! I don't know exactly if there is anything else I'm going to need for my Koi pond. <Mmm, do read the articles, FAQs files on Pond Design... you may want to reduce the width dimension, make the pond a bit deeper... and the sides steep/er... with careful digging, perhaps support/walls of sorts... much easier to maintain, and seasonal and diurnal changes in light and the problems, other changes it brings about reduced...> I know about the fast chemical treatment (because I have well water) and I know that Koi love to dig up plants (so no expensive plants for me). So, I have ordered a chemical testing kit, as well as some water conditioners. <Very good>        I'm also getting a net just in case I have unwanted kitties and birds, and I know I need various kinds of food. What else do I need for the actual pond, like more filters etc.? <Oh yes... filtration... for sure> Also, is it better to put sand or rock/pebbles at the bottom of the pond for the fishies? <... trouble... make it harder to maintain... easier to puncture the liner...> Is it okay to use sand or felt roofing paper to line the bottom under the PVC liner, or is it better to let the liner sit on the grass? <Better to have an underlayment>        Wow, this is more than I anticipated. Okay, also, as far as putting the wood together, what should I use that is more safe or effective in keeping the wood held together? This is all I can think of for now, sorry it's so long. Thanks,   Robin <Threaded rod, washers, nuts... all of this is gone over on WWM. Bob Fenner>

So many questions! Biological pond design, construction    4/14/06 I am building a new pond.  I expect it will be under 3000 gallons by  the time it is complete.  It will have a waterfall with about an 8 ft. head  (from bottom of the pond to top of the falls).  So far I have purchased the  liner (EPDM 45mil.) and the pump (Sequence primer 6000). <Good products> I need direction  on where to go next.  (1)  Bottom drain.  A friend tells me I do  not need an integrated bottom drain but can use an suction-type model.   True?   <Mmm... bottom drains are great to have... your next pond or the one after will likely have... after you've done "other ways" of periodically draining the lower/est region/s otherwise> If so, what do you recommend. <Read here: http://wetwebmedia.com/PondSubWebIndex/pdplumbing.htm> (2)  Second, since the  Sequence has an integrated basket strainer, do I need a skimmer? <Mmm, yes... perform different functions actually... and much easier to use a surface skimmer, clean this... rather than the strainer (intended really only to keep large objects out of the volute)>   My  concern is that the skimmer could allow air into the pump - not good! <Uh, no and no> If I  need a skimmer, what do you recommend? <See WWM...>   (3)  Pump housing/cover.   What do you recommend for this? <See WWM... a housing is best, above or sub-grade... with provision for disallowing flooding...> (4)  Filter.  I am contemplating  purchasing the Aquadyne Bead filter because of its efficiency and I suspect I do  not need anything else to go with it (such as a waterfall filter or mechanical  filter.  Does this make sense? <Yes, and no... I would use additional filtration here... or leave space for retrofitting, adding later... which you will likely do> Thanks for your help! Liz in Lakewood <You've got a good start here Liz... keep studying, taking good notes for now. Do try to find, get out to a local "Koi club", "aquatic garden association" meeting, to see other folks ponds, get their direct input re what they did, would do now... Bob Fenner>

Regarding formal pond construction   1/7/06 Hi Robert,    I came upon your insightful tutorials online and thought perhaps I could trouble you for some additional information.  I've recently took over a job in progress.  the unit as stands is a bottomless above ground unit that is presumably constructed of block walls, and faced with slate on the outside and only a backer board / plywood type construct on the inside with a slight (translucent) Thinset type cementous veneer.   <Good description, poor choice of materials> like yourself, I'm generally inclined towards (and therefore more experienced with)  EPDM installations, and have limited experience with concrete installations.   I was concerned that it would be difficult to retro-install the bottom on the assumption that the bottoms are conventionally installed prior to erecting block wall structures as per the guidelines put forth by the AKCA Guide to Pond Construction.  your internet tutorials alluded to such not always being the case.  could you give me any further reference as to your recommended process? <I don't recommend the backing material course period... too likely to fail>     Secondly, I've never attempted to plaster or Thoroseal a surface a surface as described above.  will I need to topically install another layer of lathe over the plywood / backer board / Thinset to effectively adhere the Thoroseal?   <Yes> I can provide you some photographs that may be beneficial if you so desire.  any information is greatly appreciated.  thanks in advance. Scott <Mmm, to expedite this knowledge transfer, I'd check into your local "waterproofing" companies here... unless the job can/will afford the use of a constantly immersed elastomeric... I would not do it. Bob Fenner>

Outdoor Pond With Viewing Panels - 10/24/05 Hi, I would like to construct a pond that enables viewers to see the contents of the outdoor pond, as if it were an indoor aquarium. I don't know how I could possibly do this. Maybe if I could somehow seal the liner to a piece of Plexiglas? HELP! <A neat concept, project... have responded to similar queries... here: http://wetwebmedia.com/PondSubWebIndex/pdconstfaqs.htm.  Best to set/seal a metal "race" frame, Silicone the viewing panel/s into it from the inside... Bob Fenner> 

Finishing a watertight concrete pond  10/19/05 Hi Bob, <Chris> First I have to say that your site has been an invaluable resource in helping a beginner like me feel that they have a handle on a project as complicated as a pond.  :)  I never would have guessed that they are such complex things! <Ah, good> I have read as much information as I could on your site, but my situation seems to be a bit unique.  I have a concrete pond which used a 4000psi mix with fiber mesh added, poured overtop a mesh and rebar foundation. <Summat like the construction of a swimming pool> The concrete itself is completely watertight. <Mmm, not really>   However, the concrete was beginning to set as the contractor was trying to shape up the surface, and as a result we did not have the time to get a nice uniform surface on the concrete.  In some areas the surface is very jagged where rocks surfaced, or has crevices and voids between 1/4" and 1/2" deep. <Yes... usually such "pools" are surfaced with a "cement plaster coat"... actually white/Portland/plastic cement, sharp sand and water... perhaps with color...> I have put some pictures for you to see here: http://www.chrispitude.net/index.php?album=house%2Flandscaping%2F10_16_2005&dispsize=1024&start=0 Start at IMG_8798.  To see more detail, choose "Original size" in the dropdown box at the bottom of the image. I do not wish to let ice have an opportunity to form in these crevices.  I'd like to put something on the concrete surface which will both fill in any voids, as well as provide a uniform slightly rough surface for organic life to grow on.  Thoroseal seems overkill for these purposes, since my concrete is already watertight.  I saw a "heavy duty masonry coating" from Quikrete at the local big box store. What should I use to get a nice rough sandstone-like finish on my pond? Thanks Bob! <Mmm, if it were me, mine, I'd (quickly, as the longer you wait the less anything will "stick" to the existing work), decide on whatever... and have it applied, apply it. First off... this is really hard work... heavy, caustic (alkaline), and can be very hard on ones back. Being lazy and well-too experienced, I would seek out the professional services of a "pool plastering" company... You'll find them in the Yellow Pages and such under "Swimming Pools, Contractors, Repairs"... They have the mixers, pumpers, folks to knock this out in a day... worth the money if you can afford it... I'd have them add an oxide (dark, of whatever color) to the mix they'll trowel on... Alternatively, you can try another "dressing"... as you list... It all needs to be applied at once... that is, the same day... so do be careful re what quantity you order (Do look into having it delivered)... adjuncts can be added, like color and "glue" to make all stickier, as well as lime for the same purpose (do wear gloves, prevent the dust from all this from getting in your eyes, on your skin... I do use Quikrete's inexpensive post mixes... but am hesitant to suggest their other products... Again, I would at least get a few contractors bids, input... If you do the work or they, the basin needs to be acid washed ahead of application. Cheers, Bob Fenner>


Bio Pool 10/18/05 Greetings, <Howdy> I am interested in building a bio pool for swimming and aquaculture. I live in San Diego. Any books or resources you can recommend? Thanks, Scott <Mmm, a few... the SIO library has most all written on aquatic topics... can't check out works unless a student, alumni member... And I would call, have some of the pond business contractors come out, look at your plans, give you bids on what you have in mind... And if doing yourself, and the "hole" very large, I'd have excavation folks bid to help... What do you want to aquaculture? There may be some help (technical) from SDSU here. Bob Fenner> 

Cementaceous construction inside biological ponds  9/7/05 Robert, Have sandy soil for my pond, have question  about  using mortar and flagstone on inside to make walls. Can the  mortar be toxic to fish. <Is to a varying extent, depending on make-up> I have heard of a plastic cement but can't find any  info . Bill  Oglesby <Use of plastic cement/s is advised. Are less caustic, toxic... still better to lower level of the basin/s while doing, curing this work. Bob Fenner>

OC pond construction  8/27/05 Can you tell me if you know of a good reliable builder for concrete Koi pond in Orange County, CA?  I had a beautiful Koi pond in my last home measuring 27 ft long, 6 feet deep (3 above and 3 below) and 5 ft wide. . .  I can hardly wait to get started again.  Thanks Craig E. Kalthoff <Mmm, don't know folks well-enough any more to "plug"... I would check the "Yellow Pages" directories under "Ponds, Construction" and "Landscape"... ask at the local Koi clubs who they used... visit sites the folks built who give you a bid... Bob Fenner>

S. Cal. pond help 7/20/05 Dear Bob, I am constructing a waterfall and pond at my home.  It is already dug, and the retaining wall for the waterfall and many boulders are already in place. Do you know someone in San Diego who can install my pump and plumbing for me? Many thanks, Tanya McManus <Mmm, not well anymore. Do give Dan Shoemaker of Aquatic Life Services a call and ask him this question... and the folks at KRC as well. Bob Fenner>

Building a very large pond, dam 7/19/05 Need to know the formula to calculate the yardage to build a dam? <Mmm> Do you know where I can find this formula? <Am hesitant to lead you to a printed reference... so will summarize... depends on the make-up of the soil about... May be that a construct of concrete, reinforcing steel is best. I would have a soils engineering firm come out, take a look-see. Bob Fenner> Vickie Leady

Pond construction question 7/13/05 I am building a semi-raised pond eight foot by twelve foot, roughly two and a half feet deep.  I am starting out with a footing 5 1/4 inches deep by 8 inches wide, reinforced with 1/2 inch rebar horizontally and vertically.  I am then planning on placing one course of 8x8x16 hollow core concrete blocks.  I am capping the pond with concrete pavers probably two courses. The footing is being poured on top of the existing grade and properly leveled.  The raised portion of the pond will be surrounded by a flower bed which i hope will solve the problem of grass clippings and leaves.  My question is if there should be any concern about frost line with the poured footing and if i should be concerned with it cracking or being damaged. <Mmm, yes... if the ground and air get/stay below freezing for long...> I will have a EPDM liner and underlayment inside the concrete block and form. I live in New Jersey, USA. Any information or help would be greatly appreciated. Everywhere i read and research has not mentioned anything about this concern. Thank you for your assistance. Dan <There are a few ways to thermally heat and insulate winter ponds (posted on WWM)... I would use a thermometer daily... or plan on draining the pond, plumbing, pump... during this time. Bob Fenner whose wife is from Garfield>

Lake liner 7/9/05 Hi- <Hello there> I stumbled upon your great site and Im hoping you can help me out.  My boss is planning to build a rather large lake on his mountain side property here in Ojai.  The lake dimensions are 200x100x150 and were trying to determine the best type of liner to use.  The soil in the mountainside is rather impermeableweve had difficulty passing perc tests because the ground is so hard.  Our contractor and ranch foreman recommend using a 30 mil PVC liner, but my boss is hell-bent on using a clay liner. <Mmm, I'm much more inclined to go with the PVC>   How much would a clay liner run on a lake this size? <... depends on the make-up of the current basin bottom... a mix of material has to be dished in... Likely cheaper by far than the PVC> Is it even worth using? <Yes...>   He's talked about Bentonite and Gunite.  Thanks for your input! <Not the latter... very expensive. I would have a few of the "lake consulting" and construction firms come out, bid this job. Bob Fenner> Emily Warmann

Pond construction question 07/01/05 Hi, I just read your article in WetWebMedia about building concrete and liner ponds and found it very interesting. At this moment I have a pond service company and would like to expand my horizon building ponds professionally, is there any seminar where I can learn more about this industry? <Mmm, don't think so... but a good idea. There have been instances where companies who manufactured liners (e.g. Tetra) went out and "gave pitches" formally, to folks in the landscape trades... and some of the big pond building companies have a sort of road show they haul about to towns to promote their biz...> Any suggestions in general? <Heeeee! Where to start... or better, end? Do work for someone who has done these a bit... Start smallish... maybe make a "demo" pond of your own... with a waterfall... filtration. A bunch of our old operations manuals are posted on the aquatics business subweb on WWM: http://www.wetwebmedia.com/AqBizSubWebIndex/Biz%20Index/Biz%20index.htm You'll likely gain from perusing these. Do write back should you want to chat over aspects, experiences...> Congratulations on your website. Regards Samuel Toscano <Thank you. Bob Fenner>

Pond construction... mainly 6/31/05 Just recently we added a cement pond to our back yard. And before putting water into the pond I need to know what measure should be taken to prevent leakage. <...?> A few question I have is how long should I allow the cement to cure before cleaning it with a solution? And what type of solution should I use? Thanks for your help! Diamondmind <The basin/s shouldn't leak if they've been constructed properly... some folks seal concrete with a coating that aids in protecting the material and rendering it less likely to affect water chemistry. Most installers use an acid wash to reduce alkalinity... some people just utilize vinegar here, but professionals often dilute Muriatic (3M HCl) and brush this on, rinse, pump out... These issues are covered on WWM: http://www.wetwebmedia.com/PondSubWebIndex/Pond%20Sub%20Web.htm You might avoid a good number of future issues by studying now... Bob Fenner>

Ponds--San Diego Building Codes 6/29/05 Bob, <Joe> I just got off the info line at the building information center, and to my surprise, the girl at the desk told me that there were no city code or permit requirements for ornamental ponds. I then pulled up the pool & spa codes, which tightly define pools and spas as bodies of water designed for people to go into. Should I call again, and get a second opinion on a different day? Is something fishy here? *ba-da--ta!* :) Joe Kraska San Diego CA <For home builders there are no such permits... but I encourage you to use "common sense" (whatever this is)... in making the system safe and "not an attractive nuisance"... That is, to wire all electrical circuits through G.F.I.s, have a service switch for all... six feet or more from the water... to not have the basin/s too deep, do have an area for climbing out... and to provide a fence as if this were indeed a swimming pool, to keep children from it. Bob Fenner>

Koi dying with no physical signs 6/29/05 Hi <Hello there> I have been searching your site for possible causes for the death of my fish. I have lost one a day for the last seven days. The pond is new (about 6500 litres). I left the pond for a couple of weeks before putting the fish (15 small Koi up to 7") into it. The filter and fountain were running for the entire period since the pond was filled. I had read quite a few of your responses to other owners with similar problems (fish dying with no outward signs). The fish that have died became loaners, not feeding and began swimming at a very shallow depth and would die within 24 to 48 hours of showing these symptoms. Whilst reading one of your replies about possible deaths caused by poisoning by weed killers/pesticides etc. <Or the system just not being cycled... the root cause here is almost assuredly environmental> it suddenly dawned on me that my pond design may actually be poisoning my fish. The pond is part dug and part raised and lined (not a problem). However the top edge of the pond was finished with 6" wide decking timbers. I realized, whilst reading your replies, they were made from tanalised timber (for those who may make the same mistake as me but are unaware of what tanalised timbers are, they are timbers treated with cyanide). I have made a presumption that when it is raining the cyanide is possibly getting into the water (not 100% but I think it is a strong possibility). Of course I immediately went out and took these timbers off my pond and will drain it first thing in the morning. <Yikes!> Could you please let me know your views on this? If you think I am right then I hope this information may help others who have made (or might make) a similar oversight to mine!! Ps. Great site!!! Regards Stephen Robbins <You are correct in that treated lumber can be real trouble... A sample of the water might be taken to a quality assurance or college laboratory for analysis... Perhaps the timber can be sealed with something making it impervious to water... like polyurethane... Or it can be moved, the pond modified such that water that does come in contact does not wash into the basin. I wish you well. Bob Fenner>

Sex ratios in Our Hobbyist Population, Pond Design, Construction <Please do come on out again... and up to LA if you have time/interest in visiting folks in the wholesale trade... Bob Fenner> That does sound interesting, but I have a conflict. I shall look forward to other opportunities. Fortunately, I have time. The aquarium is planned for next summer, timed with a remodel, where it will be built into a wall designed just for it (and not to worry, I am hip to the ventilation issues of such a design). <Ah, perhaps sometime closer to your actual install> I found the meeting interesting. A diverse and warm slice of humanity. Curious, though: are women underrepresented in aquaria, or was this meeting just an anomaly? <Heeee! Not uncommon... some areas have more of the tender gender involved, but rarely a majority> Thanks for the pond book, by the way. I think it's all on your site, and I therefore I've basically read it, but you probably didn't guess that I've read most of your whole web site already, particularly the pond stuff, some of it several times. :) <Ah, yes... have endeavored to place all my content (at least all that's been keyed electronically... since 1981...) that's not otherwise unpublished in magazines, books...> I do have two questions: 1. In your archetype design, you favor pulling mid grade from the pond, and not from the bottom drain. In your FAQs, you also frequently mention the risk of totally draining the pond through pumping malfunctions. Is this the only reason you pull mid grade? <Nope... the "bad water" on the bottom is more dense, better not to disturb, but to periodically vent... along with accumulating detritus> I am asking, because my design features gravity-feed from the bottom drain into a settling tank (same level as the pond), but pumps from the top of the settling tank back through the filters and water features. If the pond level drops too low, the pump runs dry, can't drain the pond. I like this design a lot, because it focuses the cleaning requirements on a smaller space (the settling tank). <The use of good-sized settling tanks is superior here... the only advantage of not drawing water from the basin/s bottom/s reverts to avoiding the danger of complete drainage> 2. You favor underlayment for all sorts of ponds (which has the ring of something intuitively correct, even though I didn't think of it myself, ha), but you don't talk much about mixed stone and masonry ponds, except the formal raised variety. My pond will be built from wall to wall rock, cemented together, partially raised, but emphasizing randomness and informality. Therefore no flat regions of cement anywhere, except perhaps in the various basin bottoms. I should expect this variation to work fine as long as the underlayment is correctly laid, and the stones are appropriately padded to prevent puncture as they are placed and cemented. Yes? <Yes... would add that I'd be using welded wire, stucco wire... depending on pond depth, as well> Joe San Diego, CA USA <Be chatting, Bob Fenner>

Small in-ground pond to build! Robert, Can you help me with some pre-planning I am doing for a small pond I am designing?  I have planned a 3' x 4' in ground concrete pond.  My questions are:  Do I need to form such a small size with rebar or will chicken wire do? <The latter will do...> I am planning to pour the concrete to a 3.5" thickness all around for the basin. Also, any special concrete I should spec that will be completely waterproof? <I would use "eight bag mix" (eight bags of cement equivalent per yard of concrete), with plastic cement...> I see you recommend a underlay liner even in concrete construction...will 20 ml. heavy plastic do? <Yes... just not polyethylene> Last question, there will be a 32" high urn that sits in the middle of the basin.  I would like the water to flow up and out of the top of the urn and recirculate....any rec.s on pump size and manufacturer? <Mmm, depends on how often you'll run it, whether it will be submersed or not. If not too often (that is, not continuously) and if it's going to be best to have it in the water, a "Cal" (Calvert Engineering) product> Thanks a million....I appreciate your feedback. Erin Foley King <Sorry for the delay. Have been out of the country. Bob Fenner>

Partly thought out pond plan Hi, we are making a backyard pond in a 3 leaf clover shape and it will have a waterfall at the top <highest ground> of the pond. Appx size is 14' wide by 14'long with a shelf that borders the pond appx 12" deep, then onto the deepest section, appx 3-4'  deep. We plan on taking our 3 sliders out of our indoor aquarium they are rapidly outgrowing it and introducing them to the pond, perhaps just for spring, summer and fall and maybe bring them back inside for the winter. My question is about keeping the water clean. I have an extra pump/filter from a swimming pool and have read about converting it into a pond pump/filter. We are doing this on  almost pennies, so I can't afford to go out and buy an expensive pump. <False economy... this pump will cost you much more money in not too long a while... in electrical expense> The finished ideal <in my head> will have a waterfall facing you as you walk up to it and I'm thinking the intake should be placed on the opposite end of the pond the waterfall is on, then run the return hose back up through the ground to the waterfall to a outlet box I'm sure I will have to make. Other than knowing we want a small fountain to shoot from the middle of it with a few lights to accent the beauty at night, that is pretty much where I'm at. I am currently pricing the wide black burlap to lay down as a pre-liner before ordering the actual liner. Please, any and all suggestions / advice  would be great...........thanks for your time, Mike K. <Keep reading... on WWM, elsewhere, re pond design, filters/filtration, maintenance, learn to use your grammar checker. Bob Fenner>

Glass Block for Indoor Pond? >Hi I am looking to build a large indoor pond and would like to use solid glass blocks for the top 1 or 2 rows of block wall for the front, [so] as to allow the side viewing of the top of the pond when sitting down across the room. I am just not sure that this is possible and if it is how you would go about making it structurally sound to handle the side loading of the water.  >>I don't see why you couldn't use the block for these top two rows at all, and I would use mortar per manufacturer's specs (do NOT use anything with algicides or any other "cides", though). Silicone may be used as well. >The wall would be roughly 15' long and was thinking of 2 rows of either 12x12x4 or 8x8x4 block. Is this something you could advise me on further? Thanks for your time and help. Mike >>Mike, I'm not sure about the rest of your question, I think Bob would be better able to answer that, but he's currently in the Galapagos (undoubtedly enjoying warmer weather than I). In the meantime, glass block should be no different than, say, pool coping blocks, try consulting a contractor with experience installing above-ground ponds, pools, etc. Personally, I'd go with the 12x, as there will be fewer breaks/seams. Better viewing, fewer seams means fewer areas for corruption of seals. I would also do a general Google for pond societies and materials used for pools and ponds. I know that many above ground ponds/fountains use brick, it seems to me that the glass block can be treated the same way. Marina 

Can you help me with my POND? Dear technical support, <Okay> Need your recommendations to seal Glass to Concrete, with the following basic specs for a pond environment.....CAN YOU HELP? <Maybe> Water is to be on the LOWER SIDE (left hand side) permanently and length of glass panel is about 2.6 m long and rises about 1 m vertically. Basic Gap is 20 mm wide (by depth as shown) that needs to be sealed.       <Insert graphic from desktop>    50 mm Laminated Glass Panel                                                                                    (200mm High X 20mm wide) GAP (150mm X 20mm wide) GAP Waterproof Reinforced Concrete      S Nino Stamboulakis <It would be far better for you to set a metal race in the reinforced concrete, and adhere the glass to the metal, the metal to the concrete with a water-proof epoxy... if there is not sufficient space/gap to insert the metal flange... I might try nesting the glass in a very thick bed of Silicone... can be purchased in a tub versus tubes... and made a bead, remove the excess from the glass while it is setting up. Bob Fenner>

Reflecting pool Dear Mr. Fenner, <Hi there> I am architect in Karachi, Pakistan. I would appreciate your input on the most effective construction methodology for reflecting pools. <Okay> The project is the headquarters of a large pharmaceutical company (Aventis). The landscaping includes a generous sized reflecting pool in the front of the building. The concept is to have a "as clear as possible" reflection of my main facade. <I understand> The pool is about 1'-6" deep. My main question to you is whether the tiles I am using at the bottom of this pool should be a dark color or a light one for the sharpest reflection on the water surface? <Lighter... though more of a maintenance problem. More light reflected with light color... but more algal growth as well.> I look forward to your response Thank you, Sincerely, Amina Nasim Jan Senior Architect Ahed Associates. <Send along your specifications on filtration, circulation if you'd like. Bob Fenner>

Indoor Pond camera site Here's the link to our pond webcam site: http://www.members.shaw.ca/jsherrington It features streaming video feed of our indoor pond with details about its construction. Thanks, John <Very nice. Will post on our pond subsite. Thank you for your efforts. Bob Fenner>

Just what is a keyway in a farm pond ???????? <I know this as the principal input or output point... a gate to let water in or out. Bob Fenner>  


Koi Pond possibility I love Koi Carps but never owned them. It always has been a dream and recently, I purchased some land by a hillside with a stream in the front and a beautiful natural waterfalls. This is a remote area and everything is natural. The average temperature through out the year would be 17 degree C. <Sounds very nice> It is my thinking that Koi Carps have survived many hundreds of years without pumps, filters, aerators, skimmers or any mechanical devices. Will it be possible for me to keep Koi Carps in a pond without these devices? <Yes... is done in many parts of the world... even in Japan in places like what you describe.> Rain water will be harvested and used as a natural falls to fill the pond and an outlet will be in position at the bottom to remove water from the pond to maintain the required water level. What else do I have to do? <Mmm, hopefully the basin will be large enough volume-wise and deep enough to discount large thermal swings... and not freeze all the way to the bottom during winter...> I may sound very stupid and it may not be feasible at all, but your suggestions and opinions will be appreciated <Does sound reasonable... and a definite asset to your property and life style. A few details to be worked out, alternatives to consider... like what, if anything to make the basin waterproof, other livestock to consider (maybe some planting berms for lilies, bog plants...), the possibility of having a pump, maybe a filter of some sorts, should you experience low rainfall... Bob Fenner>
Re: Koi Pond
Bob, Thank you for your quick response. I had my doubts in my belief but your reply has reassured me and given me the confidence to go ahead with my project. I do not want to make any mistakes and please direct me to sources from whom I can get more detailed information which will be of use to me in constructing my pond. <A good deal of my (demonstrable) input is posted on our sites: http://www.wetwebmedia.com/PondSubWebIndex/Pond%20Sub%20Web.htm and I will gladly help you along the way with specifics as you come up with questions> I would like to contact specially those who have similar ponds like I have in mind to learn from their experience. Please help! Thank you once again. Dudley Devaraj <You know, there may be an "agricultural extension service" in your area... they often have very valuable info. re what to expect, how things are done locally. You might try the phone book in the government sections, or a university re locating them. Bob Fenner>

Polyurethane for Concrete injection and waterproofing. Dear Sir, <Sanjay> I am a waterproofing contractor and using acrylic polymer based, epoxy based and styrene butadiene rubber based material for my work of concrete waterproofing, structural repairs, restoration and protecting concrete structures. <Have used some of these products... "between-slab" applications only... and never been happy with them. Expensive and do not wear well> But I am not satisfied with the performance of the above material because of the not satisfying results. I heard and read much about polyurethane material for above all purposes. I don't know much about polyurethane. I am interested to know about polyurethane and how it can be used for construction and concrete problem solving purposes. <Some types of jobs can work very well with polyurethanes> Your web site is very informative and interesting. At presently I have three challenging projects are in my hand. One is of polyurethane injection grouting and another is construction joints which expand and contracts because of structural design mistake of missing expansion joints in the slab at a prestigious project of science city, India and next project is of a leaking basement vault approximately 500 feet long, 20 feet wide and 10 to 25 feet various height under ground at different levels. <... I would have a manufacturer's rep. or two and structural engineers review the use, application here> Please send me broacher, technical data of all the products and method of application thereof. <Don't have any to send. My input is from years back (14 plus) and on the user side, for ornamental aquatics (ponds, fountains) only. Not human-habitable structures> I would also like you to send some samples injection grouting material and polyurethane coating for water proofing material if it is possible. I am ready to bare the cost of samples if any. <I/we have no way of testing> Kindly confirm by e-mail before sending me broacher that you can send samples or not so that I can ask for samples of the particular material I require from your product. Kindly send detailed price list and packing sizes available for each product. Waiting for your reply. Thanking you Yours truly Sanjay Bhavsar <Again, I would contact the manufacturer of the product lines you intend to use, and local structural engineers for their input. Bob Fenner>

Pond with a view Hello there, you have been so helpful with my marine problems; I can't help share my pond concerns and thank you in advance for your wisdom. I'm in the design phase of a pond approximately 5000 gallons that will have a viewing panel in the adjacent attached sunk in patio. My question is - how the heck to you get a good seal on an acrylic view port that will be about 2' high and 3' wide? Is Acrylic even the best material for outdoors without direct sunlight? We are in Tucson and are hoping to go with a cichlid pond as opposed to the Koi pond which is why we so desire a side view into the pond. Thank you for your time. Bill Roh <I've done this a few times years past. Best to have a "race" frame built, pinch/fit your liner into this and nestle the viewing panel into the frame with silicone. Bob Fenner>

Pondering and ponding in S. Africa Hello Robert, <David> thank you for a very informative website. I feel slightly more confident on my plans for my ponds now. I will hopefully be adding my name to your list of South African pond builders soon. <Ah, good... "when in doubt, dig". Bob F> David Banks Rondeberg (Philadelphia) Cape Town South Africa May the best of your past be the worst of your future. "Anything forced can in itself not be beautiful." - Xenophon <As it is not itself. Bob F>

How to construct an outdoor pond with a natural clay base. HI! <Hello> I am a new pond enthusiast who recently acquired my own home.  I want to put an in-ground pond in my yard.  I would rather like to construct it with natural elements instead of using a commercial liner.  Is this possible?  My idea was to dig out the pond and line it with clay, then incorporate sand, gravel and silt.  Is this a feasible idea?  We aren't talking about a huge pond here... <Can be done... with inspection, provision that the water doesn't "get loose" as in percolate through the bottom... Do look into "soils engineers" in your "Yellow Pages"... and have someone out to inspect the prospective basin/s. Bob Fenner> Thanks. Taso  

Building a wildlife pond I live in the mountains of Colorado with considerable wildlife, including bears who love water.  Two years ago I built a wildlife pond using a  liner,  not considering how vulnerable they are to puncture.  The bears, along with the dear and elk,  loved the pond and a mother and her two cubs made the most of it.  Of coarse the pond started leaking the first summer and I realized my mistake.  Was thinking of purchasing a very well made heavy duty pre-formed fiberglass Koi pond but after reading the articles by Fenner Roberts  it sounds like fiberglass may also be problematic when tested by bear claws.   What do you think?  Is the preformed fiberglass my best bet or would you recommend some other construction technique?  Or should I just give it up? <I don't give good odds to the longevity to a fiberglass pond here... Is there any way to bring in "chicken wire" and concrete (shotcrete even better) to make this a "cement pond" (shades of the Bev. Hills Hillbillies!). This is about the only method of building (over the liner) that I think will hold up in your setting. Bob Fenner>

Pond design and construction help Aug. 23, 2003 Greetings: I started excavation for a 100'x50'x 3-5"deep backyard pond. After reading some of your articles, I realized that I need some expert advice and guidance, if not construction of the pond itself. I only want to have to do this once. <A good idea IMO for all folks... the savings in re-doing, lost time... makes this very worthwhile> I would like some names of pond contractors in the san Diego area including yourself if you are in the area. thanks for your help.  Scott Jordan <Been a good while since I was actually "in the life/trade"... and don't know the folks who are currently. My approach would be to contact the contractors in "the Yellow Pages"... interview them (ask "what can you do for me here", "what are my possibilities")... and a list of their "selected customers" you can contact re their work... Is the pond to have livestock in it? Is it on private property (only?)... there are some other sources of help that you might avail yourself of (like the SD Koi Club)... Bob Fenner>

Tiling the inside of a Koi pond Can anyone help me with the pro's and cons of tiling (with ceramic tiles) a Koi pond. Thanks <I'll give it a go Ken: Principally what comes to mind is the expense of the install, the fact that the tiles will quickly become coated with algae et al. and look the same as if the basins were not-tiled, and how very slippery the pond will be to work in... Bob Fenner>

Colored concrete To whom it may concern:  I'm inquiring the use of concrete colorants in concrete mix to add color to the rock i make for  fresh/saltwater aquariums or a suggestion that would add color to it instead of the gray dull color it has  thanks  ..great site you folks have.......Jeff   <As far as I know the oxides used for coloring cementaceous materials are non-toxic to aquatic life. If in doubt, you might try a bio-assay (keeping some of the colored material in a tank with some "test life" for a few weeks). Bob Fenner>

Copper pond G'day, I am currently making a water feature from a giant riveted copper (used to be used to wash clothes in about 100 years ago). Its made of copper and I'm wondering if there would be a problem putting fish in it? I would be grateful for any help you can give, thanks in advance, Kind Regards Katrina. <Unfortunately yes. In years past our companies had occasion to build/retrofit copper cauldrons (used to make beer!), copper clad (old fountains)... and yes, even in higher pH water, enough copper would leach to kill most all life (and definitely fishes). I have heard of people sealing the copper with resins (hot coat, laminating...) and then placing life in such vessels. Perhaps you can inquire if such coatings are available to you. Bob Fenner>
Re: Copper pond
G'day, thanks for your quick and informative reply, I will most certainly look into it, Kind Regards Katrina. <Real good. Bob Fenner>

Re: trout ponds where should i look for info on constructing a half acre trout pond. many thanks <Mmm, a few places. The "extension service" of your State's Fish and Game for help in selecting species, seeing if your water is suitable. Our pond site: http://www.wetwebmedia.com/PondSubWebIndex/Pond%20Sub%20Web.htm for design, construction background. And then on to folks in your area who have earthmoving gear, electrical and plumbing experience... Bob Fenner>

Residential Waterfall and Pond Gentlemen,      I am in the process designing a waterfall and pond, which will include a waterwheel, to operate the water pump. If you could provide the information I need to start this project, I would greatly appreciate it. Sincerely, Paul Jagla <Yes, please read here: http://www.wetwebmedia.com/PondSubWebIndex/Pond%20Sub%20Web.htm especially design, siting, plumbing... Bob Fenner>

Pond construction, glass topped! Hi all, I am planning to build a pond/tank for my office.  I plan to make it a 7 foot circular tank with the top of the tank at the floor level.  It will have a glass top that people can walk on.  The glass would be 19mm thick and very heavy.   How do I clean the tank if the glass is not movable? <With difficulty. Best to make it removable, and buy a set of "glass moving tools" (ones with handles that you can "suck out" the air, pull the glass up if/when need to and have the glass cut in parallel pieces of such a weight that they can be tilted out (with a gasket supporting their edges (built into the floor)> I will build an overflow with the filtration, heaters and  aeration.  Can I build in filters which would allow me to run the tank without moving the glass?  I know this is a very strange request and I could not come up with a plausible answer.  Any suggestions would help. <I've been part of this sort of project (marine and pond systems set into the floor of restaurants). We placed all mechanicals, controllers above grade (higher than the basins)... and primed (filled the plumbing) with water, used check valves to keep primed... can be done... and I suggest you think over, set your pumps, filters et al. above grade as well. Much safer, easier to work on. Bob Fenner> Thanks in advance. Karun

Academic pond builder My name is Sean Fitzgerald, I am a third year at Leeds University studying for a degree in Environmental Engineering. My final year dissertation involves proposing the location of a large scale fishing pond which is actually going to be constructed. I have to look into several factors of the process, starting from planning right through to construction methods and liner materials suitable for the task. I would be very grateful if you could please send me any relevant literature you might have that could be of use to me. This could be anything from drainage systems, construction methods, suitable pond life or anything you feel may be useful. <Glad to help. Most all of my liner construction, pond, aquaculture components pieces are archived on our "Pond subweb", whose index is here: http://www.wetwebmedia.com/PondSubWebIndex/Pond%20Sub%20Web.htm Do contact us if there are particular questions, input you'd like. Bob Fenner> Yours sincerely Sean Fitzgerald

Pond Liner Bubble We have a 1 acre pond which was lined with a nice thick liner a while back. <Nice> In the past few days however it has developed a 25' diameter bubble in the middle (see attached picture). Any ideas on how to fix the immediate problem and prevent a future recurrence? <Yikes... I wonder as to the cause... the make-up of the gas itself... Some way needs to be devised to install a vent...like a "sideways drilling" operation... a pipe to the area directly underneath this bubble, water, liner... to allow the gas to escape... Perhaps a well-drilling co. in your area can help... If you had known of the gas problem, perhaps shaping the basin to be more conical would have prevented this condition. Good luck, and do have the gas checked... it could be something flammable. Bob Fenner> Thanks, Glenn A. Hartzog

Lake/Pond in the Vineyard Dear Mr. Fenner: For some time now I have been planning to put a lake in our vineyard and have begun the search for an landscape architect experienced in such projects. In surfing the net I ran across some of your writings which indicates you have much experience in lakes/ponds. If perhaps you still do such projects in California I would like to hear from you. If you don't, then maybe you could recommend someone to me. We are located in San Miguel, next to Paso Robles, and you may contact me by email at: marty@meekervineyards.com or by telephone 805-467-2624 (w) or 805-467-2029 (h). Thanks for your help. Marty Meeker <Mmm, it's been a few years for me being out of the actual "doing work" part of waterscape design, construction... and I don't know anybody that well anymore to actually suggest... I will gladly help you (for free) if you have specific questions, plans... and will post your search for help on our site for others to contact you re input. Bob Fenner>

pond shoreline design problem Hello folks <Cheers, my friend> I have been referred to your site by someone who answered one of the posts I have placed on several boards regarding this problem. <welcome my friend. Do be sure to visit the home page at www.wetwebmedia.com and navigate the links to our many articles and FAQs. This is one of the biggest websites that you will ever see... over 300 megs!> Before I ask my question I noticed someone with a home made food question, could I refer you to http://www.easyfishkeeping.com/fishyforum/forums/message.asp?r=forums&t=General&I=1040 I now know about WNV but my fry have more than doubled in size on this diet in the past week. WNV is not a problem in the UK that I know of. <outstanding... thanks kindly> Anyway to get to my question or problem. Back ground first I have built( finished building last night, just touch ups and this shoreline left) a concrete pond of apprx 2200 UK gal 2600 US gal. It has three depths, 4', 2', 1' and vertical walls. I will be using a plastic liner, pvc or DuPont Xavan, I can afford butyl. The pond is above existing ground level by 1' and will have a visible wall on 2 sides, a hedge on the 3rd and a rockery with waterfall on the 4th. I will 'line ' the concrete with expanded polystyrene sheeting ( Styrofoam, I think ) to protect the liner rather than use underlay. <indeed, many materials used here... old carpeting, parched clay, rendered sand, layers of newspaper, etc> BUT Basic outline of my problem. I want to cast, in cement or concrete, a ramp on top of the upper coarse of block work to create a semi submerged shoaling shoreline. I intend the ramp to start 2.5" below the water surface and for it to rise to 0.5" above the water surface, gradient 1 in 3. It is to allow animal access/escape to/from the pond. <very nice> For the purposes of this post I am concerned only with the construction problems, I have taken into consideration my possible UNWELCOME visitors and here in the UK we don't have the diversity of predators that exist in N. America, I hope the rest of the pond design will keep my fish safe. <very well> I see 2 ways of completing my shoreline 1) bring the liner up over the ramp, or 2) bring the liner over the top of the inner leaf of block work and drop it into the air space, then cast the ramp on top of the liner and outer leaf . I favour the second method, it will be neater and provide a better surface finish. Obviously I will seal the ramp with some thing like G4 or P1 ( common UK sealants ) but I am troubled by the "triple point" where water, liner and ramp meet. <agreed as I am concerned too. There is also the concern of longevity and repairs/replacement of the liner. The plastic and PVC liners in particular have had issues with longevity and UV stability. The latter method would not be at all forgiving if repair or replacement needs addressed> How do I seal this properly? I had thought of 'painting' the sealant across the junction and onto the liner but I have been told that solvents in some solvent based sealants may damage the liner, i.e. G4.  <agreed> I can get water based sealant which should be ok, P1. <yes... but I am still not sold on the practicality of the design inherently> Other solutions based on idea 2 are 1) In addition to the above run a bead of silicone aquarium sealer around the "triple point" , possibly in a rebate cast into the cement and cut out of the polystyrene <poor adhesion to plastics particularly in temperate zones> 2) Bring the liner up 'behind ' the back of the ramp so that the liner finishes above water level, but this may create neatness issues also it doesn't provide a secure foundation for the shoreline. <actually I like this solution best thus far> 3) Cast the shore line in sections, seal all of each section and then 'glue' it down onto the liner with silicone aquarium sealer. <likely very temporary (3-5 years before failure IMO)> One area I will have to silicon goo is the folds in the liner where they pass over the block work. Additions resulting from replies to my posts are 1) cast the ramp in waterproof concrete, a simple idea that will help greatly, why didn't I think of it and does away with "3)" above <agree... hydraulic cement was the first thing that crossed my mind above when I read "ramp in water". Quite durable in water> 2) cover the triple point with liner seaming tape. <also a temporary solution in my opinion and unlikely to even see 5 years of service> I would be very grateful for your thoughts on my problem and solutions and for any ideas that you have. Thank you Sean McKinney <I don't know if I've been much help, but I sure have enjoyed hearing about your fascinating pond. With kind regards, Anthony>

UK Pond info Anthony, excellent, thank you very much for the information. <you are very welcome...keep asking questions and learning> This is new to me so your tips are valuable. <do be sure to add a few good nooks to your collection for reference. I like John Dawe's "Book of Water Gardens" for fundamentals and construction tips, and I like J. Allison's "Water in the Garden" for stylistic guidance. Two of the many good books on pondkeeping to own. Kindly, Anthony> best regards, Steve

INFO SOURCES (concrete engineering) Dear Sir, Do you know of where I can acquire any good DIY books on the subjects of concrete formwork and reinforcement. I would like to know how to cut, bend, splice and tie steel rebars and how to build forms for concrete columns and decking to support suspended concrete floors. I don't know if I am contacting the right person, but would be grateful if you could spare this little trouble to help. My name is Shelton Daniel and I reside on the Caribbean island of Saint Lucia. <Hmm, have been to your Island... and fond memories of the twin peaks... and Sandals projects... but do info. on the type of DIY you mention.... except maybe: Masonry Design Manual, 3d edition, James Amrhein, James Kesler principal authors, by the Masonry Advancement Committee, 1979... my old standard reference for such matters. Bob Fenner> Regards & Thanks in advance.

Pond Safety I am interested in decorative ponds but was alarmed when I heard the  statistics regarding children drowning in pools without fences, and  in ponds. Do have any information regarding how to physically make a pond safer? >> Not much that I feel will comfort you or I... children can, will get around most any, all barriers... unless they're "swimming pool" safe... like six foot fences. If the system is huge, consider a "safety bench" or area of shallower depth, around the perimeter... Landscape, rockwork around the edge often works as a deterrent.... and some folks have used electrical lines (low voltage) to keep animals and maybe small people out of their ponds...  Bob Fenner

Aquatic Gardens

Ponds, Streams, Waterfalls & Fountains:
Volume 1. Design & Construction
Volume 2. Maintenance, Stocking, Examples

V. 1 Print and eBook on Amazon
V. 2 Print and eBook on Amazon

by Robert (Bob) Fenner
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