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by Robert (Bob) Fenner

Removing Old Glass Window from Pool (Human Aquarium)     6/6/18
Hello WWM Team -
I know you are mainly about aquariums and not swimming pools, so this is not a typical question. But not every pool has a window in it. I have to say I was inspired to put one in after seeing Harry's Underwater Bar in Hawaii (long since closed).
After reading your posts, it looks like you guys have the expertise to recommend a solution to my problem.
I've attached some photos of the pool window in question.
>Some?//// 28 megs of pix Matt? Why do we ask that folks limit pix to hundreds of Kbytes?<
The current window is approximately 2' x 6' and is comprised of four 1/4" sheets laminated together to made a 1" thick window. It doesn't leak, but there are stress cracks that started to form in the interior layers so I need to replace it. The window sits on a brass plate and rests against a large 2" x 2" solid brass frame with a significant amount of silicone sealing it to the frame (as you can see in the photos).
<Ah yes>
It is important to not damage the brass frame in removing the glass since we would want to use it to mount the replacement window.
<Yes; agreed>
We had the pool tiled after the window went in and you can see that they installed tile on the pool side to frame the window. We have removed the tile to see what we're working with. At this point there is nothing on the pool side of the window that holds it in. Just the silicone seal that runs the width of the brass frame - 2" wide and about 1/8" - 1/4" thick all the way around. Strong stuff to say the least.
What would you suggest I do to break, dissolve or otherwise remove that silicone seal? Heat doesn't seem to be an answer. It seems like an oil-based product would help loosen the seal on the glass side, but getting a sufficient amount worked into it appears to be near impossible.
<Mmm; no solvent will work, and no to heat. What you need, want are sturdy, sharp tools... AND careful use. There are "razor blade" tools that can, will cut the Silicone away from the glass AND brass AND surrounding area. Most all this needs to be cut away to remove the glass, THEN single edged razorblades (in a holding tool) to remove most all the rest, THEN a solvent (Toluene is my favorite) to remove all the remainder of the olde Silastic>
FYI - Our plan is to replace the broken glass with 1" thick acrylic.
<Okay... 1.5" would be better, deform less... I'd put up a sign on the outside asking folks not to touch (scratch) the acrylic>
Looking forward to hearing back from you. Any help or suggestions are welcome including a company or someone in the Southern California area that may be able to remove it.
<Mmm, there are fabricators that could find you help here. Call Ridout Plastics (www.eplastics.com/‎)  in San Diego and ask them>
Matt B
<Welcome. Bob Fenner>

From outside

contacts, Not saved on WWM      6/13/17
Dear Wet web I know this is an unusual request.... I was reading your Q and A's and I noticed there was a question from a help with converted pool; algae posted on 7/2/15
...Dear Bob Fenner and Crew,
Howsit Lou Anne?...,
from Pasadena, ca, well I too, live in Pasadena and have converted my 25000 gallon pool into a pond with turtles and fish. I am having the same problems (we seem to have started our conversions about the same time) I would love to get in contact with her and talk about our ponds, can you please contact her and give her my info
Tamara XXXX com
I would really appreciate it. With many people wanting to do this pool conversion I was hoping that there will soon be a form for just this particular project. thank you so much
Tamara T
<We don't retain folks contact information unless they expressly request to post it Tamara.
Do please peruse the files archived on WetWebMedia.com re pond algae issues and swimming pool conversion. Bob Fenner>

Koi for nursing home, Ftn. retrofit/  3/4/10
I would like to convert a 10 foot by 10 foot fountain that is only 2 feet deep to a Koi pool for the residents of our nursing home. The fountain has a fiberglass coating over brick and cinderblock and has a 1500 gallon capacity. I would like several Koi due to the larger size that the resident's diminished vision could still see.
<Best to start with smaller specimens (tategoi)... have grow to capacity, setting...>
I would love for them to be able to hand feed them. This fountain does not freeze as we are located in coastal, southern, South Carolina. The fountain already has a skimmer and a pump inside the fountain for aeration.
<Need a good-sized filter...>
With an adequate pump, filter and UV light could I maintain 2 - 3 Koi and have relatively clear water?
The pond is a central point in our courtyard, immediately adjacent to the dining room, so appearance is important. I also plan to have a few water lilies.
I don't think water hyacinth is kosher in South Carolina due to problems that have occurred in lakes here. Some of our residents are taking part in this project so I would appreciate any suggestions you could provide us.
<Have them peruse our Pond SubWeb:
My only pond experience was when I used a bog garden to filter a pond and this option won't work in this setting.
<Ahh, agreed>
I would like to prevent algae bloom.
<Hopefully there is space to locate a filter system of use... there are a few stock choices...>
The existing pool water has been treated, although I have discontinued this practice.
<I would acid/bleach wash the basin to remove residual... see the SubWeb above re>
Would this pre-existing water still have a problem establishing micro organisms or new pool water problems detrimental to fish?
<Might well>
Again I appreciate any suggestions and have enjoyed your responses from other queries. Have a good day. Scott Ewing
<Specific questions derive responses in kind. Bob Fenner>

Pool Conversion 3/30/09
Dear Robert,
I am wondering if you have any information, or maybe know of somebody who could advise me what the best way would be to convert our tiled  in ground swimming pool to an underground rainwater tank? We have lots of  roof area. The pool is 40 feet by 12 foot and is never used. We are very  short of water, and this would be an answer to our predicament. I have  asked about, and nobody seems keen to even give me advice.  I would be most grateful for your advice.
Kind regards,
Lyn H.
<What specifically are you looking for? Info. on putting up rain gutters, the plumbing to the pool from there? Whether to use a cover to discount evaporative losses...? BobF>
Re: Pool Conversion 3/30/09

Dear Robert,
We are just wanting to put some sort of a lid on top of it, and one that we can "convert" into an outdoor floor area to have BBQ's on. Would this work? Is there a product other than cement?
<Mmm, yes... a few other choices...>
Some sort of marine timber?
<Do look into the many "faux" wood decking possibilities... These often require a sub-platform for real support, but can be very attractive and long-lasting>
I guess we need some sort of advice as to how to do it, and what materials to use? Also if your firm does it, or if you know of one that would tackle it?
<Mmm, don't actually "do" any applied/work anymore... Do look at the "Yellow Pages" directory books and online equivalents... get bids, ideas from a few contractors... And DO check with your local building codes... A good idea to actually plan on treating this collected water as if it were to be put to potable uses. Likely your extant pool equipment can be of partial use here>
Am wondering if this helps? The area almost joins the house, but there is a 10 foot patio between, and our idea would be to put a roof, which could be cut into the existing house roof, over the patio and this new covered area.
<Look to getting, having sturdy gutters (plastic if my choice) installed... perhaps with leaf traps/excluders... and enough slope all the way around to convey the collected water to the downspouts on the new roof>
Kind regards,
Re: Pool conversion to rain cistern 3/31/09

Thank you so MUCH for your help.  I will take it all on board. When you say look up the yellow pages, who would we contact regarding this sort of work?
<Oh! Landscape and waterscape (likely listed under the former) companies>
I have rung around the pool people, but they have no suggestions , except to tell us we are mad !!
<Mmm, not mad in my estimation, but visionaries... I have several friends in as many countries that collect "run off" for potable and agricultural purposes...>
Is this a builders job?
<Maybe. Perhaps including other trades/skills, like architecture, engineering... best to keep investigating, keeping good notes at this juncture>
AGAIN, my thanks!
<And you, BobF>

Pool to Natural Pond Conversion   03/22/08 Dear Mr. Fenner I read your "Pool to Pond Conversion" article and it mirrors my KISS approach. I've got a waterproof hole in the ground in good shape w/plumbing and filtering, what's so hard about making it a pond. BUUUUUTTT I have been having a devil of a time trying to convince any pond builder, pool renovators, or landscaping firms in the PHX area of it. Everybody wants to rip out the pool, fill it in, and dig a pond. How do I find a builder in PHX that wants to do it my way? <Mmm, I'd try the Yellow Pages...> Here's the details: I live in Phoenix, AZ where it is VERY hot in summer. However, I have become intrigued by the "Natural Swimming Pool/Pond" concept.http://www.totalhabitat.com/P&P.html So I am converting my 1987 style pool. I want to retain as much of the pool and it's plumbing as possible, mainly because it is exactly where I want the pond and I am frugal It is a large 'ish hole- a kidney shaped, shotcrete/Marcie w/3' of Kooldeck surround, 16'x35'x3'>8.5' deep (486 sq.ft surface, 90' perimeter, ~18,500 gal). For several reasons I want to retain much of the shape and size of the current pool. In addition, to the normal 2" bottom drain and 2" skimmer, I have 14 (yes, fourteen) 1.5" bottom cleaning returns that sweep the bottom of the pool with jets of water. These could be converted to flow in the opposite direction in a snap, so I could have 15 bottom drains or even a combination of drains and returns. I also have 2-1.5" returns near the top edge on opposite sides of the pool. I have a 1HP pump <Mmm, I'd check around... re getting/using a pump that is VERY energy efficient... the one you have is very likely engineered to produce a good deal of head/pressure... that you don't need/want...> that feeds a 4.9 cu.ft sand filter at a current 6000GPH. <Bingo... I'd be reading re better filtration... for bio. systems... at least switching the media out here... as the present won't work for long> I want to build a large (~35% of pool surface area about 3' deep) regeneration zone i.e. veggie filter, <Neat!> but outside the pool on the level ground. Plants grow here year round, but in summer I am wondering what plants will survive the warm/hot water in the filter. <Likely not an issue with such a large heat sink (the pool volume)> The water from the filter zone will return over a waterfall. Am I nuts? Any suggestions would be appreciated. Thank you again. Chip <Not nuts... or... perhaps we both are...! Can be done, and be a real asset... and fun. Bob Fenner>

Pool to Pond for Humans and Fish  1/14/08 You mentioned in one of your answers that a pool could be converted to a pond in which humans and fish could swim with the right plants. What plants and how do we do it? Thanks, Susan Wilson <... How do you do what? Swim? Or convert to a combo? Please read back on WWM re such conversions. http://wetwebmedia.com/PondSubWebIndex/poolpdconvart.htm and the linked files above. Bob Fenner>

Convert fish pond to lap pool 12/30/07 Hello, <Hi there> We have a 9 x 18 foot fish pond and bog pond (waterfall) that we would like to convert to a lap pool. Our fish pond holds 4200 gallons of water and the bog pond holds 42 gallons of water. The pond has a sequence pump and a UV light. <Okay> The pond is 4 feet deep with fully cemented sides and a 60 mil liner installed. We have had the pond for 6 years now and there is no problem with it. We would like to utilized it as a lap pool without the fish. What we like to know is how do we go about this? How do we sanitize the pond, etc. and what kind of filtration system do we need. Any information on this would be helpful. Thank you. <Can be bleached to sterilize... the current mechanicals can be used... but you will need/want much more circulation, other filtration added (just mechanical) to give you a current to swim against... There is gear, are folks who can help you engineer such. Bob Fenner>

Pool to Pond Conversion, sealing the old plaster   12/5/07 Dear Bob: I have an old pool that came with a house that I just purchased. I am trying to convert it into a fish pond. The pool, as far as I know is solid and does not leak. The plaster is old and I plan to knock off any loose stuff and put a color sealant on the entire surface. <Do take care here... eye protection, heavy gloves, Levi-type pants... the cement plaster is sharp! And heavy at times> Unfortunately, I verified with Thoroseal that it requires a concrete surface and cannot be applied to pool plaster. <Correct> I am looking for a dark color sealant that I can apply to the current pool plaster, do you have any recommendations? And how long would these sealant last? I am in San Diego and wonder if there is such a product available. Thank you, Theresa <Mmm... I do have suggestions... but expensive... W/o seeing the state of the current plaster, the work behind it (no re-bar shows through I hope/trust) my carte blanche advice is to have the pool re-plastered... in a color of your choice... but will cost some thousands of dollars... On the extreme other end of the spectrum, I would leave all as it presently is... the algae/overgrowing the present poor plaster will not matter in appearance... In-between, you might look into Thoro's other consumer products like Water Plug... or similar from the fine Dry Lok product line... for partial or total re-coating... Do mix only small batches. DO get some help if doing this yourself... as it is very tiring to apply. And, of course, do feel free to write back if you have concerns, further questions. Bob Fenner>

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 titer 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>

Converting Baqucil Vinyl Pool to Water Garden  - 05/29/06 I enjoyed reading your web pages about converting a swimming pool to a water garden.  I have a pool that has slowly been reaching an age and need of repair that now has me considering converting it to a water garden.  You discussed the need to change the water out and to do an acid/bleach washing.   My pool has been on Baqucil for about 10 yrs.  I do use an algaecide, but that will go away quickly.  I have uncovered my pool for this year and have not started it up yet, while I am deciding what I want to do.   I have an 18'x36' pool with 3 ft in the shallow end and 8.5 in the deep end.   Draining, cleaning, and refilling is a big job not to mention the amount of time to drain and refill.  I would appreciated your thought on this if you have the time. Thanks Jean Mann <Can be done... the chemical residue should not be a problem with a thorough cleaning, acid-bleach washing, rinsing, dumping/refilling. Bob Fenner>

Pool to pond conversion   4/18/06 Dear Robert, We are planning on converting a swimming pool into a freshwater pond. Have read your most informative articles. Q:  Some have mentioned that we do not need to empty the entire pool. Do we need to empty pool completely? <This is strongly advised, yes. How else would one clean out the existing pool chemicals?> Please verify if we do indeed need to do this, it is a lot of work and will require a vacuum pump in place for the  duration of water removal time, so this is a but tricky.  There is no service in Maine available to do this procedure for us. <Not hard to do in any case... many small pumps available that will adapt to garden hose...> Q:  Can we leave the existing liner? <Likely so> Please respond at your earliest convenience, many thanks, Carole <Do read over re filtration, maintenance... the time to retrofit gear for this is during this conversion process. Bob Fenner>
Re: from Carole in Maine   4/18/06
Bob! You are lightning quick! Can we talk with you now?  I'd like to call if possible...Please send your number, only a quick call... <Mmm, don't do calls... Can you pen what you have in mind? BobF> Carole
Re: Pool to pond conversion   4/18/06
Bob, Thanks for your help, we finished the meeting with the landscaper who will be doing this conversion with me.  The question remains, what to do with the chemicals.  If we drain the pool and clean as advised, we will have not only a pool full of chorine to dispose of, but also the cleaning agents you recommend, with rinse water. <Mmm, mainly the tri-isocyanuric acid is a concern... and even that... not a real problem> The only way to get rid of all these chemicals is to pump them out into the pasture.  No one here will take them away, it is far too rural, no services of that sort around here. Any suggestions?  What have you done in the past? <Dump into the sanitary sewer or onto the ground. The acid and bleach are made from seawater... Hydrochloric and Chlorine... and "turn back" into this when combined... over time... a bit more salt> This is a big deal, we are an organic farm and are hesitant to send any more chemicals into the environment than is already there. We inherited the pool upon purchase, and ridding the place of chlorine is important. <... Mmm... well... if it were me, mine I would pump it to the pasture likely... unless you have a very large septic system, are going on a long holiday where/when you can pump all to this. The bit of soap et al. detailed in the "acid bleach washing" AP are of little concern health wise... and will not permanently damage your pasture. Bob Fenner> Again, thanks. Carole
Re: from Carole in Maine: Pond from pool conversion  - 05/13/2006
Bob, I have been discussing the pond conversion here in Maine.  The pool is 15,000 gals and 6 foot deep at the deep end.  People here seem to think it would very hard to properly aerate this pool, even with a good $3,500 ozone system installed.  Please tell me what you think. <Mmm, there are other means... but ozone will definitely aerate/oxygenate, do the best> I am on the verge of having the whole thing bulldozed down, I cannot get a solid opinion on this project, it seems. Thanks, Carole-Terese Naser <An ozonizer incorporated with an aerator (in-line) is about ideal here. Bob Fenner>
Re: from Carole in Maine: Pond from pool conversion  - 05/13/2006
Bob, Have you done this before in a pool this size, with this much water? <Have done this... with systems of much more gallonage> DO you have pics? <Not out where I am currently (in Hawai'i for the month)> Can you get me to someone who actually owns such a system so that I could talk with them? I'd be forever indebted, Carole-Terese <Mmm, was years ago... our business ended in 91... BobF>

Converting a large pool to a pond Hello, my name is Hope and I have rather large above ground pool in my yard. I want to make this a pond. the dimensions are 20' wide x 40' long. it starts at 4' deep and declines to 9' deep. right now I have no fish but I want to raise channel cats and blue gills as a food source... oh I will have 1 Koi, a gift from the neighbor... I want to use a bio filter system, home made of course, right now I have large 55 gallon drums, I have 3 of these. my neighbor raises Koi, and said I the contents should be pea gravel on bottom, with as much "sponges" I can pack in the drums... she recommended a pump to pull up from the bottom of this filter. I was thinking that a filter made with a layer of pea gravel then sponge, then more pea gravel then sponge... <Please read here: http://www.wetwebmedia.com/PondSubWebIndex/upflowfiltpds.htm and the linked files above> ...and so on until my containers are about 3/4 full would be better... I was thinking that since I will be unable to lift the filters , that I should pump into the tanks from the top and use the holes in the bottom as an outlet... <Yes, agreed> this way I can lift the lid to remove the gunk from the top few layers of the filters...I have cross walks to get to the filters. my main question is... is this do able this way? my next would be is 3 55 gallon filter systems enough and what size pumps would I need?  I have no plants right now, but I intend on a few and possibly some sea weed. Thanks Hope <Please start by reading here: http://www.wetwebmedia.com/PondSubWebIndex/poolpdconvart.htm and keep reading... the linked files above... Bob Fenner>

Who Can Do It? >Who can convert a pool to a natural swimming pond in southeast Louisiana - Mississippi? >>I don't know, don't live there. Have you tried the yellow pages? Marina 

Abandoned swimming pool to pond Hi, I was just wondering if its possible to convert an abandoned swimming pool to a still water pond without draining cleaning and refilling (there's water restrictions in place)? <Possibly> Our pool has not been used or maintained for in some time (years so the chlorine residue should be gone shouldn't it?) <But likely too much chloride (salt)... from the previous chlorine additions> and I was wondering whether it could be converted into a still water pond? I say still water because the pool is only 8/10 full, but no where near the level required for the filter to run and the filter is really old too. <Should be... I would "blind pot" your plants... place the ones that need shallower water on cinder blocks...> Is there any fishes that can survive in pretty much stagnant water (and that eat mosquito larvae, the pool is a breeding place for many insects)? Cheers, Will <Quite a few... decide what sort of "atmosphere" you'd like... an aggressive/predator one with some local game fish let's say, or an overall peaceful one with livebearers like platies, Mosquitofish, Paradisefish... depending on your seasonal water temperature range. Do have your water checked for salt content and importantly "stabilizer/conditioner" (tri-iso-cyanuric acid) as these can be too toxic... You may need to drain, acid wash the sides, plumbing... and re-fill. Bob Fenner>

Converting a Fiberglass Pool to Koi Pond From: Willard&Elvira. Thompson. Summerville. South Carolina. Dear WWM Crew: Your expertise and knowledge is needed: Could you help us?. <I'll try> We are in our late 60's and our 4 year old 6.200.00 Gallons Fiberglass Enclosed (and Heated in winter) Pool in not used much any more, as now I (Elvira) have both hips and left shoulder replaced with Prosthesis. <I see> We will like to use it as a Fish Pond, our Koi, Shubunkins and Comets are small, from 4" to 7". Pool has one of those Fiber Optic Lights that change colors, can be set to any of the Spectrum. <Neat> Will Fiberglass hold the chemicals used in the Pool?. <To some extent yes... should be drained, acid-washed (dilute Muriatic, about ten to one with water... rinsed, refilled, tested, some test life added after a week or two...> Pool is very clean, good filter etc, and adding more Bio-filters as the 3 we use in our outside Pond, will not be a problem for Hubby and Son to install, our concern is what residuals could be in the Fiberglass, as it can not be totally empty, is in ground and 4' deep for Children safety, Grand's grown now. <Not much does precipitate, adhere, but best to be sure... some folks, times I've seen rock salt, a bit of water and clean pool brushes, extension poles used... but the acid-wash is the best... do with good ventilation, or have someone do for you> Any suggestions and how to make it safe for our Finned Pets?, the Dogs x 3, been drink in the outdoors Ponds, total volume 300 Gallons, as they are 2 connected, fish on higher only, not harm to the fish so far. The Pool enclosure has 2, 8' garage doors one on each end and 4, 4'x62 inches windows, clear sides and roof no to reflect UV Rays, big Fans at both ends to keep it cool in summer, 6 Umbrellas to keep Sun of clear sides, not Algae. <Very nice> Thanks in Advance, any help will be deeply appreciated. Willard&Elvira. <Please read here: http://wetwebmedia.com/PondSubWebIndex/poolpdconvart.htm and the Related FAQs, Articles (linked, in blue, at top) and write back if there is something/s missing or unclear. Bob Fenner>

Swimming pool to pond conversion 9/04 I think I may have written you before and if so I apologize for bugging you but I am interested in talking to someone about whether it is practical to convert my little used pool to a pond and the cost. I am in the Chicago area. John Voortman <I see from your next email you have found the article and FAQs pages on WWM re this project... and I'll post both messages on our "daily FAQs" hoping that someone will respond in your region. I encourage you to scan the Yellow Pages, phone directories under "Landscape" or even "waterscapes" and interview folks who list that they "do" ponds. Bob Fenner> Sorry, I just found your page again and that you had answered my prior e-mail (I m  far from an expert on the internet.) I am interested in getting the names of contractors in the Chicago area who might be interested in doing the initial work. John Voortman

Converting pools to ponds I have a little used  liner pool and am interested in finding out whether it is practical to convert it to a pond and what it would involve in conversion and maintenance costs.. Your name came up in my internet search. <Can indeed be converted... likely needs a preparatory wash, few rinses to rid of possible chemical residue (scale, salts...), some testing for residual chlorine... a waiting time of a few weeks, perhaps modification of existing plumbing/circulation and filtration gear... otherwise, mainly selection and placement of livestock choices. Please begin reading concerning such conversions here: http://wetwebmedia.com/PondSubWebIndex/poolpdconvart.htm then on to the related FAQs and articles (linked, in blue, at top). Bob Fenner> John Voortman
Re: convert human swim pools to ponds that are safe for humans and fish and plants to share
I followed your requests and searched the archives and board chats to find the same issue but to no avail. <This piece?: http://www.wetwebmedia.com/PondSubWebIndex/poolpdconvart.htm> Pool Background info: I designed and built a custom pool for me ( Lap-Swimmer Mom), and my three sons: Son #1: competitive diver/swimmer, Son #2:  special needs, right-hemi CP disabled who walks, talks, etc. after swimming therapy his first 4 years, Son # 3: Super Baby, who swam, talked and potty-trained himself by 18 months, yet had congenital Asthma cured/healed by 14 years of "lung expansion" from swimming. NOW...in real time the Super pool is down and empty and in need of a new purpose. I do not want the expense of refurbishing it as a private conventional swimming pool nor do I want the hassle of maintenance and/or use of CHEMICAL treatment. I want to "swim with the dolphins" in my back yard (goldfish and water will suffice!) sooooo.............My question is: Is it possible to create/convert a Gunite Giant swimming pool into a self-sustaining, bio-balanced multi-purpose POND for all? <Yes, have seen this done. Depending on initial water quality (nutrients, mineral content of source water) can take more time, careful types of plant selection to achieve, maintain balance. Bob Fenner>

Feedback for WWM Hello WetWebMedia, I write to thank you for providing this wonderful website, free. We are a couple living in Bacchus Marsh, Melbourne, Victoria, Australia and are thinking of converting our swimming pool to a water pond. Your website gives us inspiration to continue with the idea. Thank you again. Marg and Phill Scarff <Thank you for your kind note of acknowledgement... very encouraging. Do keep details of your efforts and send along a pic or two as you go. Bob Fenner>

Fish Project Things in Zimbabwe are getting tougher. I am wondering about keeping bream in my swimming pool. Somebody has said they can offer me some plant life from the lake. <A worthwhile project> The type of fish I am thinking of keeping are called Nilotica (Nile Bream) <As in Lates nilotica? Please plug this scientific name in at fishbase.org. Is this the species in question? I would not try to raise this animal in your pool (there are better choices... for food or ornament... like some of the larger haplochromine fishes> What considerations do I have to take into account? <Take a look on WetWebMedia.com on the "Pond subweb" under converting swimming pools to biological ponds: http://www.wetwebmedia.com/PondSubWebIndex/poolpdconvart.htm and the linked FAQs (in blue, above) file> I thought of keeping a few ducks to help break the surface from time to time. <Depending on what you're trying to do (optimize fish/protein growth), keep the water a tad clear/clean, you'll need to do more than this... as in add aeration, possibly mechanical filtration> I also thought of growing the plants out of pots in the pool. <A much better idea than not using pots> Masvingo, in Zimbabwe has a warm climate. <Yes. Have a dear friend (he's lived with us a dozen years) who lived in Swaziland for fifteen years... who regales us with his travels in your country often> Please help me with some information. Mike <Please make it known which direction you'd like to explore. Bob Fenner>

The draft Bob -- here's the draft. If you can see a way to make it more of a how-to, let me know how to! This is just about the right word count, so keep that in mind. Also, what are DE sleeves?  <Diatomaceous Earth... swimming pool technology... made of plastics, never to be scrubbed...> Thanks! ---------------------------

Converting a Pool to a Pond Do you have an old swimming pool on your property that's just gathering leaves? Don't backfill it. You can easily transform it into a large water garden. It may be made of Gunite and reinforced steel, but even if it's a liner pool or in need of re-plastering and re-tiling, you can still convert it to a Koi pond or other waterscape. Most of the hard work is already done. The hole is dug, the dirt has been hauled away, and the plumbing and electrical are in place. All you need are a design idea and the energy for a bit of clean-up and mechanicals modification.

Cleaning A chief concern in converting a swimming pool to a working water feature is the removal of any chemicals and residues from the surfaces. Pool chemicals such as cyanuric acid and conditioner, chlorine, and bromine are general biocides that kill all forms of life. These need to be completely removed. A procedure called acid/bleach washing used in both swimming pool and ornamental aquatics maintenance will accomplish your goal. Drain the system, apply a water-diluted solution (about 1/10 Muriatic acid) to the basin, plumbing, and mechanicals surfaces (be sure to remove filter cartridges first), then rinse and drain two more times. Wear rubber gloves, old long-sleeved shirts and slacks, and eye protection. Like so many things in life, once you've done this cleaning it will seem simple and straightforward. Basin re-coating, plastering, and retiling will probably not be necessary, as the coating from algae in the pond will eventually hide any flaws. Just take care not to slip in your new pond should you have occasion to step into it.

Circulation and Aeration For full-blown Koi (Nishikigoi) systems, the pump needs to run continuously. The pumping mechanisms installed for the swimming pool are likely not the best available or most appropriate technology to use with your conversion. Most fully rated swimming pool pumps are designed to produce relatively high volume at high pressure. You will want some volume at not much pressure for your pond-to protect aquatic life as well as save on electric costs. Do your homework here, as there are some good choices in fractional and multiple horsepower pumps for ponds that can be retrofitted to the existing pool plumbing. Compare power-curves, water moved per kilowatt consumed, and service factors, because the pump operation cost will probably be your greatest ongoing expense. On the other hand, if you will operate your waterfall only when guests visit, or if the pond will be a reflecting one only or a heavily planted water garden, your current pump may work just fine operated manually as needed or for a few minutes to a few hours daily on a timer. For Koi and other vigorous oxygen users you may need to turn the water over quite a bit, while mainly plant systems need far less circulation. Generally, you can continue to use the main drain on the bottom of the pool as the pump's principal intake, rather than supplying another mid-depth intake. If you circulate your water daily and are good about maintenance (removing sludge and leaves) you will probably not have difficulties with stagnant water or stratification in your system. If you live in an area where freezing is a concern, consider deicing mechanisms, surface agitation, air-lift mechanisms, or the use of a small submersible pump to keep your water moving. Filtration Swimming pool filters are made to remove small amounts of small materials from the water. Biological ponds call for extraction of larger quantities of larger matter. If your pond does not collect many leaves and has good biofiltration from aquatic plants, you may be able to remove the existing filter media (DE sleeves, cartridges, sand) and instead use plastic biomedia, ceramics, fused glass beads, or batting material in place of your existing filter's "guts." For Koi ponds and other more serious applications, a filter specifically for ponds is definitely required. Construct a large container inside a new waterfall, or use an inline series of plastic troughs. Even in-pond filters will work; however, these need to be well-planned to expedite maintenance.

Retrofitting Your conversion may need new plumbing for intakes or discharges such as waterfalls, to improve circulation, or to allow for the passage of more water without resistance. If so, use Schedule 40 PVC pipe and fittings. Copper pipe already in place is safe for your aquatic animals; because of its patina, very little copper ion released will be precipitated. If your pool has a heater, leave it and its plumbing as is or have them removed or retrofitted to lessen pumped water drag. Skimmer intakes can be problematic in pool-to-pond conversions. Am excess of floating matter and even fish can become trapped in such areas. Screen the skimmers with plastic mesh of sturdy construction to prevent a tragedy. If you decide to retrofit your existing pump's plumbing, don't miss the chance to cut in barbed intake and discharge fittings on Ts and valves on the new pump's intake and discharge lines. These can be a real boon in regular vacuuming maintenance and occasional, large water changes, allowing you to pull out the water and place the waste where you want it. Maintain your new pond the same as you would any other irregular-sized and -shaped biological pond. Fish-feeding, plant potting, re-potting, and fertilization will all follow the same schedules.

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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