The Crash (algae going sexual)
My names Andrew and I'm a college student in LA. I'm doing a research project for my English class on the subject of Refugiums.
<Man- all that we studied in college English was dangling participles, iambic pentameter- not even wet/dry filters...Man- things have changed!>
I have done plenty of interest as I'm building one for my 75 gallon reef aquarium. What I'm asking is if you can recommend any sources or information on the Term; CRASHING. Crashing as in when the algae in the refugium turn sexual during the hours that light is not running over the refugium. If you could help, I would greatly appreciate it. Thank you for your time and thanks for having such a site. Its been very helpful in the past with my reef aquarium. Andrew
<Well, Andrew, I'd start by doing a search of the FAQs on macroalgae on the WWM site, possibly using the word "crash" to see what comes up. Otherwise, you should investigate Caulerpa, which is often associated with "crashing"! Also, do check out Anthony Calfo's "Book of Coral Propagation" for more info on macroalgae and their use/abuse/benefits/pitfalls. Good luck!  Scott F.>

Re: Refugium
Dear WWM crew,
I'm in the process of starting a 24"x24" refugium in my sump.  What is a good on-line source for Caulerpa?  
<Check the links at Wetwebmedia.com I hesitate to recommend any specific etailer. There are numerous choices.>
What quantities and type?  
<Have you read about the pros and cons of using Caulerpa? This is also catalogued at WWM.>
Does Caulerpa require quarantine or special acclimation?  
<Many aquarist suggest QT for anything added to the aquarium. I personally only quarantine fish. But I am aware of the risk inherent in this method and I accept those risks. Acclimation is similar to the acclimation of fish and corals.>
Do you recommend other (types/quantities/acclimation/quarantine) critters for the refugium as well?
<I suggest starter cultures of copepods, Mysis shrimp, and similar critters. No fish. You can start your search with Inland Aquatics and IPSF (Indo Pacific Sea Farms).
Thanks again for your service, Brian  
<The pleasure was mine! David Dowless>

Friends Don't Let Friends Buy Caulerpa!
Good evening!
<Hi there! Scott F. here for you!>
I just recently heard about utilizing mangroves in a sump vs. Caulerpa, searched your site for more info, found a little.  Was wondering if you could give me a quick run down on the pro's and / or con's of this, was just about to set up a new sump for Caulerpa when I heard about mangroves.
<Well- first off- I wouldn't look at mangroves as a means of efficient nutrient export, like macroalgae. They grow very slowly...much too slowly to perform the same export function in a closed system as macroalgae. They do encourage the growth of various fauna within their root systems, however, so are interesting in that regard. You should purchase a copy of Anthony Calfo's "Book of Coral Propagation" for some really cool information on using mangroves, as well as more good stuff on macroalgae and nutrient export. A must read, IMO.>
I am looking for a natural way to lower nitrate levels so I can start adding corals, liked the Caulerpa idea because I could cut off excess growth and feed to my ever-grazing Naso tang. Current tank is 120 gallon fish and liverock only with 29 gallon sump.  Thanks for any info you can provide, love your website!!
Doug
Edwardsville, IL
<Thanks for the kind words, Doug! Although very popular, Caulerpa is not really the best choice for a purposeful macroalgae, IMO. After lots of personal research, reading, and discussions with the likes of Anthony Calfo, Eric Borneman, and others, I have concluded that there are more drawbacks than benefits to Caulerpa use. This stuff grows like a weed, true- and if harvested regularly, can export nutrient efficiently. However, should you rip segments of the plant through careless harvesting, many potentially noxious chemicals from within the plant are leached back into the water. Also, these algae have a tendency to go into a sexual reproduction stage, potentially releasing enormous quantities of gametes and other cellular material into the water, negatively impacting oxygen levels, among other things. I'd look into more "docile" macroalgae, such as Chaetomorpha, Ulva, and even Halimeda. They offer many of the advantages of Caulerpa, without much of the detrimental effects. As Anthony likes to say- "Friends don't let friends buy Caulerpa!" 'Nuff said! Good luck, and have fun working on this project!>

Small refugiums
Anthony -Thanks for the advice.  In regards to the refugium, I do not have a sump,
<oops... my mistake. I should have mentioned that I distinctly prefer and recommend upstream refugiums... almost never sump style. This refugium could simply be a drilled 10 gallon aquarium on a shelf just above the main display, decorated attractively and hopefully fishless for optimum plankton culture>
and I am unwilling to drill my expensive glass tank and void the warranty.
<your warranty is easily voided by the manufactures who rarely back them up anyway (I don't blame them either with the variances in floors/stands, etc)... for starters, if you didn't buy their stand to go with their tank: your warranty is voided>
Having made the initial mistake of not having a drilled tank, I am trying to find ways to create the most stable reef environment possible.  The CPR Fuge is the only option that I have seen w/o going to box type overflow that will sooner or later dump twenty gallons of salt water into my house.  Do you think there are better options with my limitations,
<yep... the upstream 10-20 gallon fuge>
or do you think that the incremental gain given by an inferior refugium is not worth the added expense.  
<I sure don't think you will be getting enough bang for your buck with it, but you may feel differently>
If you have DIY ideas for a hang on style refugium (or any other
commercial options) I would be interested.  
<I do not recommend any hang on refugiums... by nature and need they are too small to be effective>
Thanks again for your great advice.  James
<best regards! Anthony>

Refugiums
Good evening gents.
<Hi Ron, How can we help you?>
I have a question that I hope you can help me with.  I have a 55g mini reef with a 5g sump.  I am looking to add a refugium to this set up.  Have you had any experience with the CPR Aquafuge Hang-on refugium? 
<Many in use, small buy useful for smaller tanks.>
Also I have read about putting the refugium on the opposite day-night cycle as the main tank.  My closed brain feeds at night, won't this be counter productive?
<How will providing natural food when this organism feeds be counterproductive? If you are referring to the residual light, this is usually not a problem in standard refugiums located separately and above the main display. You might try a barrier to block the light, regular aquarium backing or contact paper will work.>
One last q...  If I do go ahead with the refugium I may have to place it below the tank, is there a way to minimize the death rate from the return pump?  And are there any DIY plans for making a refugium on the site?
<Try: http://www.wetwebmedia.com/refugium.htm  Look into low shear pumps for refugia located below the display. Also, follow the links to plumbing marine systems for more useful info!>
Thanks, Ron 
 <You're always welcome Ron!  Craig>

Jaubert Method Refugium
Hello again! As always thanks for your prompt responses and considerable patience with what probably seems like an endless supply of repetitive questions. Anyway, I have decided to construct a refugium (after researching www.WetWebMedia.com) using the plenum method and a 4 inch sand bed.
<Ok>
I will alternate light with my main tank and will not keep any burrowing fish in the refugium.
<You should not keep any fish in the refugium.>
What would you recommend as a good flora/fauna starter kit and what type of inverts should I avoid placing in the refugium?
<I would obtain some live sand, a few really good pieces of live rock, and a detritivore kit or two. The idea is to seed the refugium with a broad diversity of critters and using multiple sources and media accomplishes this well.>
Also, I was thinking of using Natures Ocean live aragonite (.5-1.7 mm) diameter for the entire 4-5 inches and just adding maybe 1 inch of the same per year as it dissolves.
<I would save your money and buy dead sand. If you want to buy some live sand, obtain this from your LFS or online retailer, not from a bag that is sitting on a shelf for who knows how long.>
Mr. Fenner has suggested using a two layer method with inert screen in between. Is this simply to prevent burrowing animals from getting to the lower layers.
<This is a description of the Jaubert method and I would have to defer to his writings, Dr. Jean Jaubert. You should be able to find his actual writings with a quick search.>
I understand that different microorganisms prefer different grain size so if I stick with one type (see above) will I be able to sustain a well rounded population of microorganisms?
<The fine grain sands seem to be the best.>
Thanks again!
<You are welcome. -Steven Pro>

Quick plumbing question
Hi guys,
Sorry to bother you, but I wanted to get a second-opinion on what I'd done when I plumbed my refugium into my sump.  I have a pump that pushes water from my sump into the refugium and then it overflows back into my sump.  I've pulled power on this and it presented no problems.  I did have the refugium return just pouring into my sump from about 8" above. This was noisy and REALLY increased the humidity level inside my aquarium stand.  So to counter this, I added a piece of PVC tubing that extends down below the water level of my sump.  There is probably 12"+ height
difference between the two water levels (the refugium being  higher).  I figured that the bulkhead overflow would provide air to prevent the tubing from acting as a reverse siphon or anything.  Does all of this sound safe to you?  As I write this, I'm thinking that I should just temporarily cut the power to everything to make sure.  All the same, please affirm/warn me of what I've done.  Thanks!
John
<I am trying to picture this, I think I've got it.  The refugium overflows into the sump, and there is a pump in the sump returning water to the refugium?  Sounds good to me as long as the return is either higher than the overflow, or has a small hole drilled in it at the same level as the overflow to break the siphon in the chance of a power failure.  -Gage>

Refugium
I'm endlessly deciding between two configurations, and can't afford to do it wrong based on the cost of my custom fabricated filter. I can either mount my skimmer in the sump of my 24" Berlin sump and have a 15"x16"x20" (roughly 20.88 gallons) refugium or mount the skimmer outside the sump in a more traditional setup. I'm looking at the +/- game. What good is a refugium that is hidden under a cabinet?
<Aesthetically...no good at all. However, all of the reasons that one keeps a refugium (zooplankton, phytoplankton, growing useful algae, etc. are still valid.>
Can you still make good use of it?
<Absolutely!>
Also, as far as lighting goes, how do people get the proper sized lighting strips for custom size refugiums?
<Check with the Custom Sea Life website. Their link is on Wetwebmedia. They may have just what you're looking for!  Good luck! David D.>

Refugium Startup
Hi, another question that I hope is worthy of your answers.
<Hope that my answer is worthy of your question! Scott F. with you tonight>
I have read (just recently) on your frequently asked Q and A's that one or all of  y'all suggest an upstream refugium that will produce 'pods that will feed the system and the corals?  Is this possible and what exactly would be put in the refugium that would be able to produce quantities that would be able to feed my fishes and my corals?
<Certainly is possible. You could use various grades of substrate (Course substrates tend to produce amphipods, medium to fine substrates encourage smaller species, like copepods, floating forms of macroalgae, like Chaetomorpha, provide refuge for Mysis populations) to encourage the growths of different creatures.>
I have a 180 gallon acrylic with a 60 gallon acrylic aquarium as a sump, with numerous corals and fish.  My tangs are voracious eaters of frozen Mysis shrimp and also greens when possible.  I also have several other fishes that would join in the smorgasbord.  I have been thinking about a 24" hang on refugium by CPR and need to know what would be a possibility as far as stocking the refugium with live critters that would produce enough to keep my inhabitants happy or content.  Any ideas or insight?
<The refugium that you are considering could certainly produce enough life to supplement your feeding, but not enough to rely on it. Do read some of the many FAQs on refugiums that can be found on the wetwebmedia.com site, by using our Google search feature>
Where would I get live starter critters that would reproduce in the refugium? Thanks as always, Jeff
<Some can naturally be found in live sand and live rock, or macroalgae. You can also find a willing fellow hobbyist with a thriving refugium who could offer you a "starter culture" of such animals. And, of course, you can check out etailers, such as Indo Pacific Sea Farms and Inland Aquatics, which sell these creatures. Study, plan, and execute! And most of all, have fun doing it! Good luck!>

Refugium, Shrimp, Equipment, etc.
Ok... I got the message about the quarantine tank.  I don't really have the $$$ right now, but I will setup before introducing more fish to my system.  
<Money well spent Dave! You will save the price of the QT many times over in healthy fish.>
With the exception of my Mandarin Goby (and the one night stay of my Dragon Wrasse), all creatures have been in my tank for three weeks this Tuesday.  All of the fish look fine and are feeding well, breathing properly, etc...   Of note... a part of my live rock forms a small cave / cubby hole about 4-5" high and 3-4" deep, my butterflies take turns swimming in there and just hanging out... weird??  
<Normal>
The butterflies look fine, I noticed that when I first turn the lights on in my tank they are almost grey towards their tails, yet after about 30 minutes with the lights on they turn back to a pretty nice white.  Is this a camouflage thing?  
<Yep, normal as well>
One of my butterflies has slight pinkish marks towards its gills that are hardly noticeable... perhaps they were there before... but the other butterflies don't have them.  A sign of disease perhaps? Or will all fish have some sort of small abnormalities??  
<Could be signs of a problem, or an individual thing...keep an eye on them. Pink or red around the gills could be a warning sign.>
Is it best to leave what I have alone in my tank and stick to the quarantine on all additions (<-->obvious).
<Absolutely....the fish you want to get isn't going anywhere! There will still be some left when your tank and other fish are ready.>
About the Coral Banded Shrimp, Big Al's keeps the Corals in with the Cleaners and Peppermint Shrimp at the store... they always seem to have them together.  
<So does Petco and a number of other retailers. They may move through them fast enough or they are overcrowded and stressed enough to not have a problem.  Also, they are most vulnerable after they molt, which also may not happen at the store.>
Will the Coral really feast on Cleaners??  As well, do you think the Cleaners can rid the Butterflies of any skin irritation????
<Yes, and Yes, of various parasites including ick.>
I am getting some white stuff growing on my filter hoses and powerhead in my tank as well as some brownish growth on any appliance part directly under my light source.  Do I just clean this stuff off when it develops? Is that common?
<You can clean this off if you want, it will regrow.  The algae can be scrubbed or scraped off. It's very common.>
Some other stuff that Big Al's told me that I would like your opinion on -  Hey, at what point do you start charging me? hehe...
<In just a moment here...>
I have a canister filter that is good for 150gallons... I was told to clean it about every 3-4 weeks at the time of water changes (was told to do 10-15% water changes monthly).  How exactly does one clean the filter??
<Change 25%. Use the old water to clean the waste and debris from the filter media. If it has carbon rinse new carbon to replace the old.>
  Tell me if I am correct in saying:  Stick the filter 'output' hose (the one that restores the filtered water to the tank) into a bucket to lower my water level (for water change).  Lift the filter pump hose out of the tank so it is sucking air to get rid of the water in the hose so that I can move it without getting water all over the place.  I guess my filter canister should be in a tub for all the water that's gonna come out when I open it, right?  
<Bucket, tub, sink or bathtub. Just hold the hoses higher than the canister. Yes, it can be used as a siphon.>  
I should leave the water in the canister but should rinse my rock off??  Is this correct?   
<If you are referring to the rock filter media, then a couple of five gallon buckets will work. Being careful to keep the media types separate, dump the rock media into the bucket and rinse it out with old tank water (not tap water) so as to preserve the biofiltration. Use this same procedure for all reusable filter media.>
Clean all my hoses and put back into tank after I have filled up my 10-15% with new premixed salt water?
<Aged 12-24 hours, heated, aerated, perhaps buffered water.>
Is there anything else that should be cleaned on a filter?
<The impeller in the pump portion in the top.>
Unfortunately my filter is a German one and there are no English instructions... so I am going by memory from what Big Al's told me. I also have, what I have been told, a really good protein skimmer.  In "Aquariums For Dummies" terms, what exactly does this do?  
<It removes wastes and byproducts.>
I was told I should have it 'skimming' 3-4 days a month and just circulating water the rest of the time.  Is this correct??
<You should have it running and skimming 24/7/365. Your skimmer should always be running and producing dark skimmate (waste).>
I noticed it is collecting some yellowish/brown water in it's receptacle over the past 3 weeks.  Obviously I dump the 'junk' but is there much to cleaning this piece of equipment as well?  Dump the salt water too? rinse with regular cold water and replace in my tank?
<Clean the collection cup and throat daily. The skimmer should be cleaned when making water changes or if it is coated with algae and crud.  Use hot water.>
Oh the novels one could write when they are bored at work.  I appreciate all your help and sorry for the novel, but I am a rookie with lots of questions.  Thankfully, my water tests have been really good.  I have tested every 3 days for first two weeks and will get another test this weekend. Dave
<No problemo Dave, we are all beginners at something!  Craig>

Why a Refugium?
I have read the column on refugiums, and I'm still not sure if I need one or not. If I get one, it would have to be attached to my 17 gallon Berlin sump UNDER the cabinet.
<I've seen many set up this way>
Since it won't be seen, is it worth having?
<I think the benefits outweigh any perceived problems with this setup. They are a great addition to most systems; a natural producer of food, a settling place for delicate inverts, macroalgae, etc. I can't really use it for a quarantine tank, since it uses main system water.
<Exactly- don't use for quarantine!>
Should I get one for under the cabinet?
<If you want to add one, I'd recommend that you put one wherever you can install it logically and correctly. Do look up "refugiums" on the Google search feature here on wetwebmedia.com for more info. Good luck! Scott F.>

Sumps, refugiums, mud filtration, oh my!
Hello again,
Thanks for all the wonderful info that you provide. It helps to bring order to what sometimes seems a  very difficult hobby. Here goes......
I have a 215 gallon mixed fish and invert and I am in the process of setting up a refugium. I currently am using the Berlin method (350 lbs of live rock with lots of skimming). What is an ideal size refugium for me?
<Generally, the bigger the better. Anything under 20 gallons is not worth doing.>
Should the water in the refugium go all the way to the top?
<Like a standard aquarium, overflow and plumbing considerations need to be factored in of course.>
How large of a space should the plenum be?
<I am going to refer you to the published works of Dr. Jean Jaubert.>
It is my understanding that the plenum is simply an empty space underneath the substrate.
<Correct>
What are the physiological effects of the plenum/why is it necessary? Should the substrate be layered with different grain sizes (why) and separated by additional eggcrate? How should the layering be done?
<Again, with the above questions, go to the source of this methodology. Almost all problems with plenum systems have to do with improper installation.>
Is a mud type substrate recommended or a larger grain or some combination?
<A mud substrate is a completely different methodology by Leng Sy of Ecosystem Aquariums.>
What should the grain size be? Where can I find step by step plans/blueprints for the construction?
<You should be able to find out all your questions using a simple search engine on the internet.>
Should it be lit 24/7 or alternated with the main display tank lighting?
<This depends on which methodology you employ.>
Does the refugium need to be compartmentalized?
<This helps with controlling flow and surface skimming.>
Will the pump kill all the critters before they get to the main tank since the refugium will empty into my sump first?
<No, not all.>
What is a good seeding package to start with?
<Livesand and detritivore kits from several sources to increase diversity.>
What are the essential macro-algae plants that should be in the refugium?
<Again, this depends on your intentions, nutrient export, larger plankton production, nanoplankton, etc.>
My space will allow for a refugium that is 48" x 9" x 20".
<About 35 gallons.>
Will this size be enough to do the job?
<You should be some added benefits.>
Also, I have heard all the pros and cons of UV's and have decided to use one. It has been running now for 6 months. My display tank has four drains and I plan on using one of the drains for the refugium. The other three returns will drain into the sump where I have a Euro-Reef skimmer and my mechanical filtration. The pump return is Teed off and 1 return flows to chiller and the other though the UV. Both returns go directly into display tank after that. If I have the refugium return directly into the display tank, can I continue to run my UV?
<You can but it will negatively effect plankton production.>
Any input would be much appreciated.
<Please search both our site and the internet at large for refugium ideas.>
Thanks, Steve
<You are welcome. -Steven Pro>

Xenia in sump
Hello whoever,
<right back 'atcha unknown question asker>
I've got a question about putting xenia in my ecosystem sump.
<OK>
Would it hurt the xenia to have the 24/7 lighting?
<yep>
I'm probably going to give the rock full of xenia away within the next week so it wouldn't be in there for an extended period of time.
<alas... unlike the rarity Caulerpa, Xenia and most photosynthetic creatures cannot remain in stasis under 24/7 illumination. They will suffer and must be allowed to conduct respiration. It is truly your goal to export this creature alive from your tank, you must allow a day night period for the coral to prevent a potentially fatal luminary shock in time. Besides... the 24/7 lighting method is marginally beneficial at most. It has been dispelled as a preventative for vegetative events in Caulerpa. Caulerpa is prevented from going sexual by regular pruning within the known 3-6 month life cycles of more than 40 recognized species>
I just don't want the xenia to spread anymore in my tank! Would this work?
<My advice is to run a regular photoperiod for the next week for the Xenia and then return to 24/7 lighting if you like after its gone. Best regards>

Refugium Flora and Hair Algae Woes
Hello Everyone !
<Good morning! Scott F. here today!>
Have a general set-up question regarding my 50 gallon refugium. I have a 300 gal mixed coral reef tank (mostly SPS).  The reason I added the refugium IS NOT for nutrient export but for zooplankton, copepod, Mysis production for feed into the main tank.
<A GREAT application for a refugium!>
Given this, what would be a good setup for the refugium as far as the flora is concerned? Right now I have grape Caulerpa and feather Caulerpa, which I am slowly removing to make room for other macroalgae species that are less toxic/problematic.
<A great move!>
I am thinking of replacing the Caulerpa with Ulva fasciata, Chaetomorpha, and Thalassia from Inland Aquatics. Does this make sense, given that my refugium's purpose is to produce live food rather than nutrient export ?
<Great question. Yes, it does. Even though the macroalgae that you mentioned are generally slower-growing than Caulerpa, they perform some other functions that are exactly what you're looking for. Chaetomorpha, for example, is basically a Mysis/zooplankton "Disneyland". Since I switched to
Chaetomorpha, I have noticed an explosion in the Mysis population. This algae seems to provide an ideal home for them to breed and feed amongst. Ulva is also an excellent substrate for amphipod growth. Thalassia is a very slow growing plant, probably not a great choice for nutrient export, but once again supports plankton/diatom growth. Keep in mind that you need a deep sand bed for this species to root in (approaching 5-6 inches) or it will not do well. You should definitely get a copy of Anthony's "Book of Coral Propagation" for lots of interesting details on refugiums and macroalgae use. You'll love it!>
Also, I have been battling the "Hair Algae Beast" in my main tank.  I have traced the problem as being caused by the following:
1.  Protein skimmer hose (long) was plumbed into my home's water/sewer drain pipe and was clogging, yielding inefficient skimming....now I use a collection cup w/>short hose and I clean the hose while cleaning the collection cup
<Good move. A clean skimmer is essential for proper function and waste removal. Try to clean it a couple of times a week, if you can.>
2.  Lights were too old and lost color temperature...replaced and right away my anemones, clams, etc opened wider...an indication of proper wavelength.
<yep!>
3. Insufficient water changes...Now doing automatic daily 6 gallon changes
<Wow! My kind of reefer! I'm impressed!>
4. Coral die off due to high temperatures when on vacation....replaced Teclima Chiller (many problems, 3 replacements from Fritz, finally obtained refund... I do not recommend these chillers) with Aqualogic....much more reliable....0 problems so far (6 months)...
<Glad you resolved that problem>
I also replaced some of the coral which should help CO2 uptake to some extent.
<ok>
5.  Excess CO2 from calcium reactor....temporarily disabled reactor until hair algae is gone.. I have a K2R and I can't seem to get the alk / calcium that I need without using excess calcium.  Therefore I bought a second chamber and also I now run an AquaMedic Kalkreactor for makeup water.
<Quick thinking on the CO2 problem!>
6. Excess feeding.... I cut feedings in half until algae is gone
<As you know, feeding is okay, just don't overfeed! Your increased lighting from newer bulbs should make up for the lesser feeding of your corals>
Now that I have traced the problem down and made the above adjustments/changes, the hair algae is not growing back.  But the old stuff is still there....
<Tenacious stuff, huh?>
Do you have any suggestions  to get rid of existing algae? I just want to rid my tank of it  once...after it is gone I think the above implemented changes will prevent re-growth. Is there anything I can in addition to daily physical extraction, vacuuming, activated carbon/poly filter to get rid of the existing hair algae ?
Chuck Spyropulos
(banned from reef-central by heavy-metal spineless guy, Ron Shimek) hee hee hee !!!!)
<Well, Chuck, your corrections in husbandry and responses to the problems you've encountered so far have been great, and I hope that our WWM readers  can learn from your methods! Apart from employing purposeful consumers of excess algae (i.e.; tangs, Centropyge, some blennies, etc.), I think that just yanking out the stuff is the best way to go for now. If you have extensive coral population, I'd be afraid to throw in a fish that could start munching on your precious corals. Manual extraction is a pain in the rear, but I think it may be the safest way to go at this point. And- you always are free to speak your mind here on wetwebmedia! I was gonna make a joke about the food/metal connection put forth by a certain "authority", but thought the better of it! Take care!>

Refugium
I have just finished reading all of the Refugium & FAQ sections and although I have a much better understanding of them, I still have some questions on adding refugiums to smaller tanks. My conclusion is that the "ideal" setup for a refugium would be drilled and placed above the tank to be gravity fed down into the tank.
<Correct>
Unfortunately for my 30 gallon reef, I don't think either is possible. The only place the refugium can go is below the tank (space and decor restrictions), which would also limit me to a 16 gallon high, undrilled (and I have no idea how to). I would have to use an overflow on the main tank and am a little hesitant as to the reliability of them and if this would just complicate the tank for little gain.
<I hate siphon overflow systems.>
I wanted the benefit of having extra water volume and a place to grow Caulerpa or seagrass, but don't know if cluttering up the tank with an overflow for a 16 gallon refugium would be worth it, any thoughts?
<I would choose not to have a refugium if my only option was a siphon overflow system. On the other hand, this is not your only option. You maybe able to incorporate a hang-on refugium. CPR makes several models. See if any of these cannot fit onto your tank.>
Thanks in advance, Ryan Achenbach
<You are welcome. -Steven Pro>

Getting Rid of a Refugium
Hi WWM Crew,
I have a 30 gallon refugium hooked up to a 150 gallon reef tank + 30 gallon sump. I have quiet a few corals and 9 passive reef fish except the sailfin tang that I will have to return back to my LFS sometime end of this week (for obviously a wrong choice on my part). I would like to add fish or an exotic colored invert to my refugium as it looks too dull with Caulerpa only.
<Please understand that as soon as you add a fish to your refugium, it is no longer a refugium. A refugium is a place of refuge for tiny creatures where they can live and breed free from predation. Any fish you add will consume some of these beneficial animals and turn your refugium into just another inline tank.>
Is this something that has been tried or even suggested?
<Not really because it negates the purpose of building a refugium in the first place.>
What would be a good choice so that it does not eat up all that the refugium is supposed to produce for corals, etc.?
<Leaving it empty.>
Was looking forward for fish like clown pair or other small fish that lives in pairs and is interesting to watch. Smaller the better. I have also heard others suggesting a small cucumber and a couple of snails in a refugium. Is this true and should do that?
<Some snails maybe beneficial.>
Right now I have Caulerpa, miracle mud and aragonite substrate. Sand bed is about 3 inches. Your help is much appreciated as always. Here is a list of my fish: 1 sailfin tang (will be returned), 1 green Chromis, 1 false percula clown, 1 pyramid butterfly, 2 yellow Coris wrasse, 1 orange spotted fairy wrasse, 1 purple firefish, 1 fathead Anthias, 1 blue/yellow tail damsel. Regards, Razi Burney
<Best of luck to you. -Steven Pro>

New fauna refugium, Iron supplement?
Dear Crew, Avoiding Caulerpa in this box designed to breed small crustaceans,
<a good start already... seriously>
I have put in Codium, red grape, Ochtodes, Ulva, Chaetomorpha, and "tang heaven red". (can't find Sargasso or 'seagrass' suggested by Steven.)
<no worries on the Sargassum weed for smaller vessels... too fast growing>
I read elsewhere that a chelated iron supplement will help these slow growing algae and not harm the reef.
<agreed... within reason>
I add nothing without advice from WWM. Will the iron effect the rest of my reef system?
<it can benefit or harm the system like most anything else... Iodine, Calcium, etc. A good rule of thumb is that you should only dose what you can test for. If you are willing to test and monitor iron levels, then great. No targeted level necessarily (within mfg recommended range)... just prevent it from straying from untested and blind dosing. For all else, small frequent water changes will serve you as well or better (weekly recommended). With all that macro/plant matter... please be sure to always use carbon and change it often (1 oz weekly per 30-50 gallon rather than 4 oz monthly, for example). This is necessary to maintain water clarity from all of the discolorants released>
I can temporarily stop or slow the flow through this refugium or I can perhaps stop the iron at the overflow with a chemical filter. (PolyFilter or a small bag of carbon).
<no worries.. the iron can benefit coralline algae and others in the tank proper. Just don't overdose>
Perhaps you can help me identify a milky white "slime" that covers part of the sand bed (oolitic plus several live sand inoculations) when touched it comes apart like  a wet piece of tissue paper??
<strange... not sure without more to go on>
How do you feel about small hermits and/or snails in this refugium?
<snails will be fine or helpful, hermits and crabs of all kinds will almost certainly be a detriment>
Any other plankton producers that will not eat the macro algae or the "pods"? What are the "sea bunnies" offered by Indo Pacific? Would they be worthwhile?
<a snail/gastropod. Interesting but not necessary>
Thanks to Bob for suggesting this addition to my system. Howard in Wisconsin
<Anthony in Pittsburgh. Home of the awesome Pittsburgh Steelers :) Good luck to the WI folks and home team for Favre winning MVP of the year... I'm voting for him!>

Live rock/substrate and Refugiums
I've been reading your FAQs, and as a newcomer to the hobby, they have helped tremendously.
<very good to hear! Welcome to the hobby, our site and life at large>
I have 2 very different questions:
1)I have read the refugium FAQs, and seen a few pictures on the site, but I am still somewhat confused on their setup.  
<no worries... they are simple features to install and have many possible applications/places in the system>
Is the refugium supplied by overflow from the sump, and a small pump puts the water back into the sump?
<no, my friend. Refugiums are usually and best tapped inline: flow-through... either catching water from the return pump is the refugium ('fuge) is upstream (above the display) and overflowing down to the main tank...OR...it catches water from the overflow, before overflowing itself further down the line (this is a "downstream" application) to the sump. In either case, there is only one sump, and one return pump on the sump. You are simply tapping this refugium inline on the way down or way up from water making the sump loop>
From what I read, water is only pumped back into the sump, not into the refugium.  
<water is never pumped into the sump. By definition, a sump is the lowest, downstream gravity-fed vessel. It would, in fact, be dangerous to both gravity feed and pump water into a sump>
So if I wished to add a refugium to my system, I would have to
join the current sump with the refugium at the water level?
<much simpler, my friend. Your sump vessel can be placed under the tank with a drilled overflow hole that sits slightly higher than the top of the sump. The water from above drains into it and then overflows down to the sump next to and slightly lower than the refugium. on new sump installations (if the sump is large enough) you can instead seal a high dam/partition into one side of the sump to act as a refugium. It will catch all raw water first then overflow into the lower portion. These are both downstream, refugiums. Better yet for plankton culture (no pump shear) is an upstream refugium placed on a shelf just above the main display, fed by the sump pump and overflowing into the main tank>
Perhaps I am just very confused.
2) In my current fish only tank, I have between 1/4" and 1/2" of crushed coral substrate.  
<OK... but not ideal... course media traps detritus and causes algae blooms (among other things) unless you clean this gravel aggressively and often or have massive water flow in the tank>
If I was to add live rock, would organisms eventually move into the substrate?  
<some yes... not much though... too course and too shallow for a substrate>
I know they probably would with fine sand, but I'm not sure if the crushed coral is suitable for them. Thanks for all the help! Jim
<best regards, Anthony Calfo>

Muddy Issue
Hi WWM Crew,
<Scott F. here tonight>
Your site is really great and is a constant source of information to me. The tank I have is a three months old 80G tank with a 25G refugium. The refugium is having 2 inches of sand (not the live one), a few live rocks and is growing Caulerpa. I'm wondering if it makes any sense to add Miracle Mud on top of the sand to make the sand bed an inch more. Is the mixing use of
normal sand and miracle mud OK? Thanks a lot. Manus
<Well Manus, you certainly raise some interesting questions. The "Mud" concept is reliant on the growth and regular harvest of the macroalgae. A more "traditional" refugium is really meant as a place where various animals (i.e.; amphipods, mysids, and other creatures (including plankton, and even larval fish) can grow and reproduce without predators and other hazards. So- it really depends on what your primary goals are: to use the system as a natural filter, or to simply have the refugium as an extra source of biodiversity and natural food production. Yes, you can grow macroalgae in a refugium, and yes, you can grow amphipods in a "Miracle Mud" filter, but I would either use all aragonite sand (by the way, your sand will eventually become quite "live" in the refugium), or all "Miracle Mud". Do read more about these systems in the resources on wetwebmedia.com. hope this helps!>

Sump/Refugium
Dear WWM Crew,
I have a refugium question. My set up includes the following:
1. 180 gallon acrylic tank (78"x26"x24") with two internal overflow boxes (each with 1 1/2" bulkheads) that drain to sump #1
2. Sump #1: acrylic 22" L x 22" W x 16" H (for CS8-4 Euro Reef skimmer) with two 1 1/2" bulkheads that connect to sump #2 acrylic (48" L x 24" W x 16" H). Sump #1 is behind a wall. Sump #2 is under tank. I also plan to maintain a 10" water level.
3. Two Mag-Drive 12 pumps for return to display tank. Return plumbing is built into the overflow boxes and exit at the top of the tank.
Now for my question. My thoughts have been to build a refugium in the
center of sump #2. Inlets for sump #2 being near one end and the return
pumps at the other end. Any thoughts as to partitioning for the refugium,
<I would retrofit this to look similar to an Ecosystem-style sump/filter, but sans bioballs.>
substrate depth/type and lighting.
<This really depends on what you want the refugium to do; nutrient export, pH stability, plankton production, etc. It also matters a good deal what the 180 is intended to house; big messy eating predators, plankton feeders (like Anthias), a SPS, clams, LPS, soft corals, etc. Please see the information available on www.WetWebMedia.com regarding refugiums.>
Any other comments concerning this configuration would also be appreciated.
<As there is no one perfect lighting for any tank, there is also no perfect refugium. Everything needs to be tailored to you and your tank's needs.>
Thanks for your website. Brian S.
<Have a nice day! -Steven Pro>

Tiny Bubbles.... blowin' in my sump/refugium
Hello Mr. Fenner,
Rob from Canada again. We communicated over the A. nigripes last week...very pleased with the fish.
I have a worry ...I've designed a sump that is close to what Ecosystem Aquarium uses for the miracle mud.....which I am using on my 65 gallon.
The last chamber has two pumps 1 mag 9.5 for the return and a Rio 2100 which loops back into the first chamber where water from the overflow box goes .......I did this to add more flow going through the Caulerpa. I also added a MaxiJet 1200 into the chamber containing the Caulerpa and mud.
<You don't need, nor want more flow... likely less... 3,4 turns per hour is about ideal>
Problem is I have MICROBUBBLES out the ying yang going to the main tank......IS THIS A DETRIMENTAL PROBLEM for the fish or corals?
<Possibly... and one commonly put forth here>
Or is it just a visual problem?
I've tried playing with the plumbing.....and have not been able to resolve the issue.
Thanks again for your time and patience :)
<Please read through the marine plumbing FAQs starting here: http://www.wetwebmedia.com/pbfaqsmar.htm and on to the Refugium, Algal Filters... sections.
Bob Fenner>

Refugium
Hello again!
Short question. Should I add a Miracle Mud refugium to my 90 gallon tank to be plankton reactor for feeding my anemones and to add trace elements to my system or better feed my anemones with prepared food?
<I would do both. Have a refugium for its added benefits, but still target feed the anemone.>
What about yellow water problem?
<This can be dealt with by regular water changes, use of activated carbon, and aggressive protein skimming.>
By the way what is your opinion about keeping seahorses?
<Please refer to www.WetWebMedia.com for the articles and FAQ files.>
Best regards, Darek
<Have a nice day! -Steven Pro>

Lighting the productive refugium and tang compatibility
Dear Bob,
<Hi Howard, Craig here...>
Here's Howard again, now having started up the new "fauna production refugium" in series with the Caulerpa refugium. Following suggestions from you and several of your associates it has 5 inches of sugar fine oolitic aragonite along with 2 pound inoculations of live sand from Florida, Fiji, and Inland Aquatics' filters. I have put in Mysis, Gammarus, and mini-brittle stars along with other tiny stars and a variety of worms and other life (some that I must research to identify) that came with the live sand. I will add peppermint shrimp for their egg strand production and continue to look for other sources of "plankton".
<Sounds like a lot of fun. Maybe work the brittle stars out of there as they take the "refuge" out of refugium for your amphipods and sand inhabitants and you want to grow and reproduce them.>
On Anthony's advice no Caulerpa but I have found Codium, Chaetomorpha, a red grape, Halimeda, and Ochtodes. My question is what level of light I should maintain? (the Caulerpa refugium is on 24 hours, 40 watts). I can't find anything on the lighting needs of these more interesting slower growing plants. For now I have rigged a spare dual 55 watt power compact 50/50 actinic/white on chains so I can put it at any height from 2 inches up. I would like your advice as to how close I should run this fixture to make both the plants and the amphipods happy? Should I get a different fixture - halide or fluorescent? Should lights run more than 12 hours?
<Twin 55's, that's 110 watts of PC? Depending on the size/depth of the refugium this should be fine. I would use the growth of the plants as my guide. This can be run anywhere from 12 to 24 hours depending on pH stability and if that benefit is desired along with good plant growth which will happen with more hours of light.>
I am looking for a blue addition to my peaceful community - have re-read your wonderful material including the chapter in depth about tangs. I have a Zebrasoma flavescens yellow tang, one of the first 4 fish that I acquired for the reef. (along with sleeper goby, flame angel, and clown and have added neon gobies, Anthias, convicts, and fire fish gobies) In 100 gallons, would a smaller xanthurus or Paracanthurus hepatus be at risk? These are beautiful fish! Or would the smaller size and different color make it an ok addition? Macro algae food source is plentiful. As always, Bob I appreciate your advice. Wondering if this departure might work out.
<My bet is on the Yellow having difficulties with a new Tang addition if there is a problem, but this is a purely individual reaction. If you go this route do prepare for possible problems and returning the fish if necessary. Craig>

Re: Refugium Lights
Hi Bob and WWM crew,
<Hello Razi,>
I have setup a refugium after reading 1/4 of your book "conscientious marine aquarist" within 2 days. I am following what ever is in my abilities to the best but have some questions for you.
1. Can I use blue light on the hang-on refugium. I have an 18 inch hang-on from CPR. Will this disrupt the refugium life cycle in anyway. I am turning the lights on in night time which is opposite to my tank lights.
<I would use a normal white spectrum bulb. Refugium plants aren't demanding in this regard, however, I doubt they will do as you wish with just the blue spectrum.>
2. How many hrs of lights should be good in a refugium.
<Anywhere from 12 to 24 depending on your choice of plant material and own choices, i.e; pH stability.>
3. I am using Jalli 13 compact fluorescent lights. Are these ok for AquaFuge 18" refugium for a 150G reef ? Did not have any room to put bigger refugium than this. I hope it will be ok.
<Jalli is alright for this size hang-on. These hang-on refugiums aren't really the best size for large tanks in the 150 area. Maybe for 55-75 on the upper end. I would be looking at a 55-60 gallon refugium over the top of a 150 myself if I was planning on it providing sufficient food for a 150 and exporting waste for such a volume>. 
4. I have some small live rock pieces, Caulerpa and 5 lbs miracle mud in it and it has been up for about 2 weeks now. I am not seeing much happening in there yet but how much time am I looking for before I start noticing some growth in the refugium? Your response is much appreciated. 
Regards, Razi Burney
<You should be seeing growth anytime now. If your lighting is just blue, then that is surely your problem and you should replace the bulb with a full spectrum bulb optimized for aquatic plants. I would run lights over Caulerpa 24/7 to help prevent vegetative degeneration and related issues. Please see: http://www.wetwebmedia.com/refugium.htm
and the related links at the top of the page. Think 1/4-1/3 total volume to work like you want, i.e: 40-50 gallons minimum. Craig>

Re: Refugium (#2 - or is that 5?)
Good Morning!
I've attached a quick sketch of the refugium - I'm not an artist, so don't laugh, k? The water line is actually just below the spout of the skimmer, which pours into the middle section of the refugium. 
<hmm...yes, but the water is shared and not totally concentrated/isolated in the first chamber. It is here that I suggest you add a small piece of glass or acrylic to dam the water slightly higher before it overflows into chamber number two. Also, the third chamber water level should be slightly lower than then second... if the dotted line is your water level... then you have too much water in the sump. Your actual sump is simply the third chamber: that is the sump portion (the lowest/last chamber). My concern is that the volume of this sump/3rd chamber is too small for the system. Can it hold all the water from upstream in the event of a power outage? I assume you have had a chance to test this but do be sure if you haven't.>
The water flow is so fast, I'm not sure whether the sand will ever have a chance to settle! 
<yes... one of the many reasons why I personally prefer an upstream refugium and not one that is below tank or sump-integrated>
Of course, I'll have to wait a few days and see. Anyway, please see if you can make sense of the drawing, and note that the baffles are equal height. 
<noted>
Some water is going to the skimmer, as it sits in about 8-9 inches of water (the skimmer is on a "shelf" of acrylic to raise it out of the water some), but most is pouring over the baffle, into the
refugium. 
<yes... largely bypassing the skimmer>
A lot of the water is just skimming over the top of all three
compartments, and going back to the tank.
<agreed>
Is a ref. supposed to have this much flow? 
<it can... slow flow refugiums are overrated. Still the 'pods need something to culture in... spaghetti algae, polyester pads, etc>
I think my copepods are mashed to mush by now! (Yuck, soggy cereal!)
<still edible to coral and fishes <G>>
-Cathy <><
<We may need to chat by phone on this one. Best regards, Anthony>

Re: Refugium (#6, I think)
Hello again!
Ok, the third compartment, with the return pump, DOES have a lower water
level than the other two. (It didn't last night, but the water flow is
settling.) 
<evaporating...raising your salinity slightly in the process. Do be conscious of this. Target a desired running level and keep it constant with daily additions of top off water if necessary... you know the drill :)>
Just enough to cover the pump and the sponge filter on the end of
it. We haven't tested it for if / when we lose electricity, 
<Yikes!>
as this project
was finished late last night. 
<Ha! braver than I am... you build it... THEN went to sleep... testing it next day. Some concern about the sequence of events here... heehee>
Will do that today, along with the other tweaks needed.
I added a plastic lid along the wall of the first compartment (the spout
hangs over the wall, so couldn't be full-length) and that seems to slow down the rate of water going over the baffle. (The lid is on it's side, not as a covering, but an extra height to the wall.) 
<yes... a dam, per se>
Still doesn't ALL go through the skimmer, but keeps the water movement in the 2nd part going.
<not sure here... I don't think so. The raw water dumps into the first chamber... not plumbed into the skimmer right? If so, some inevitably bypasses. We are just trying to minimize that>
The skimmer has foam, but not much. Air tube is fully open, and I can't tell where the water level is in the skimmer. Why did they have to make it gray? Hee Hee. Have ordered a mixed batch of "red" and "brown" algae from Bill's Reef, hope to get some plant life going. Oh, and "Sea Grass" is included in the order.
<awesome... be sure to know that seagrass must be planted at least 3" deep. Deeper is better. That means a sand bed of around 5-6" minimum>
Great states alive, how come you guys are on the East and West coasts, but no one in the middle of the U.S.? Y'all need to come back! LOL We'll feed ya more brandy ;-)
<yummy! and with thanks! It was shared at the banquet with all friends... Bob Fenner, Leng Sy (Aquatic Ecosystems, etc)>
THANK YOU THANK YOU THANK YOU -Cathy <><
<our great pleasure, Anthony>

Refugium
Hello Anthony! (Or whichever person gets this...)
<howdy!>
Ok, the refugium is plumbed in - hubby did a very interesting job, I'll have to try and diagram it for you, or better yet, take pics.
My question is...the 55 is divided into three parts: skimmer box (fed raw tank water) pours into middle section with sand, plants, etc. Third section is return pump. 
<all sounding good>
Ok, but both "baffles" are the same height. One is NOT lower
than the other, to return to the main tank.
<not sure I follow...meaning that the first and second chambers kinda mix before the water level drops down to the third section? More specifically, are you saying that the first chamber does not drop in to the second chamber? I believe this is the case. If so... I would stop running the system... drop the water level temporarily... add a small piece of glass or acrylic to the first baffle and glue/silicone to raise its height slightly. We want/need the first chamber to concentrate raw overflowing water before carrying on to the second and so on.>
Will this cause problems, and if so, how do we fix it? Water is running
through, so too late to undo and either cut holes like an overflow box, or anything else.
<Hmmm... still not a problem. Get plastic nylon clips or clamps and clamp small strip of acrylic or glass to top of the first baffle to raise the height slightly like a dam>
Hoo boy....hope this isn't a problem, but you will probably tell me it is... -Cathy <><
<no worries, I'm sure it can be resolved>

Re: Dunno, but it's green! (2nd time)
Hey, Anthony, how did I luck out and get you to reply?!?! 
<good or bad luck <G>?>
Hee hee. Anywho, if you remember, you and Steven made a lot of suggestions for our tank. Well,
tomorrow we are adding the refugium, so you may be peppered with emails from me!
<no worries...ask on>
We got the 55 gal tank (36x19x20), the Aqua C EV-180 skimmer with Mag 7, and a Mag 18 for the return. I've printed off several drawings of refugiums, and your Coral Prop. book, to go by (thanks to all the wonderful staff and Chat
Forum followers who post their drawings!, and of course, you and friends for the book). Hubby just went to get the plumbing and the lights that are to be used for the mangroves. I'm afraid to let him roam the store by himself, he may buy out the place, but supposedly this is my fish tank, so I guess I'll let him ;-)
<ha!>
Found the picture of the Lobophytum that might be my coral - well, it sort of looks like that, but right now is only two "lumps", so I'm not sure. 
<highly variable with this genus>
The pic on the WWM has a green one, w/o the polyps. Mine is pink, and used to show polyps :( But the picture is close enough to be the same type!
<and likely is>
And being a fan of Star Trek, was hoping you would recognize that tag line - what you had was purple, but hey!
<ahhh... Star wars, not Star Trek... I limit my vices :) >
Have a good night, be bugging you in the morning, hopefully you won't hear Scott yelling from this time zone about the water that just got him in the face.... -Cathy <><
<Ha! Best of luck to you both! Kindly, Anthony>

Refugium Substrate Questions
Hi folks,
<Scott F. with you tonight>
I am going to be upgrading my 4 yr old reef tank (55G w/hang-on filter) to a 75G w/30G sump/refugium. I plan to seed the refugium with some of the seasoned crushed coral/aragonite mix from the old tank. What substrate(s) & depths would you suggest for the tank & sump, for best biological filtration? None of the inhabitants require anything out of the ordinary.
<You can use a course substrate if you're trying to cultivate amphipods, medium for copepods, a deep, fine substrate for enhanced denitrification>
Even though I am transferring water & live rock & corals into the new system, will the tank "cycle" due to new substrate in the main tank? 
<In all likelihood, yes. Do test ammonia/nitrite for a week or two before adding new inhabitants>
I am planning on weekly 10% water changes, siphoned from the main tank gravel only, never touching the gravel in the refugium. Is this the correct approach?<if you have a fairly deep sand bed (greater than 3 inches), you really should not disturb the sand bed in the main tank. Ditto for the refugium. You don't want to disrupt the nitrifying processes occurring in the sand bed(s)>
Thanks to whichever of you is kind enough to answer, and special thanks to Bob for TCMA. Could you please write similar guides to finance, parenting, and car repair? ;-) 
Scott
<How about it, Bob!><<Easily done. Bob F.>>

Refugium Question
<cheerio>
Hello folks, A quick question regarding the stocking of a planned refugium. I replaced a 75gal tank with a 150gal tank, set up primarily for SPS corals and clams (MH's, strong flow, DSB, etc.). I want to use the 75 for a refugium, with significantly less light and circulation. 
<neither less light nor less water flow is necessary or even recommended for refugiums. It depends on what you are growing in refugia. For a seagrass refugium, they will require more light and water flow than a typical reef for example (but has MANY benefits)>
Along with a DSB and 75lbs of live rock, I planned to have mushrooms and leather corals in this tank, as both should thrive under these conditions. 
<hmmm.... corals in refugiums are predators on natural plankton. The refugium in effect ceases to become a place of refuge. This tank will simply be another inline coral system. No harm here... but don't be surprised with mediocre plankton culture. Such refugia should be fishless and essentially predator-less. Heavy rubble or grasses for vegetable filtration and denitrification respectively, pod culture, etc>
However, I know that these type of corals should not be housed in the same tank as one dedicated to hard corals such as SPS. 
<ideally>
Is the planned addition of these soft corals and mushrooms in the refugium feeding the SPS tank going to be detrimental to the health of the SPS's? 
<many problems here yes... allelopathy fro the terpenoids and other noxious compounds produced by the soft coral... not top mention the reduced plankton generation for your SPS because planktivorous corals reside in the refugium>
And would the use of charcoal and other chemical filters lessen the impact that the soft corals (primarily the mushrooms ?) may have on the SPS corals? 
<yes... very helpful. Weekly water changes too in addition to aggressive skimming>
A slow moving and lower lighted display can be beautiful, as the mushrooms and leathers (like toadstools) really shine.
<agreed... a separate tank is needed here for this>
Having the 75gal set up this way, along with the SPS tank would provide the best of both worlds.
<alas... not compatible to long term health and growth of both groups>
Thanks, Steve
<best regards, Anthony>

Setting up of large refugium
<<Hi Paul, Craig here>>
Bob, I have a 450 gal reef setup, running fine. I just plumbed in a 90 gal tank that I had that was a former reef setup. Gravity feed from tank, gravity feed to sump. I had intended to set it up using live sand, live rock and the reef type lighting that was in use before. My LFS has suggested I go with mud, Caulerpa set up as it would suck up more nutrients. What would you suggest, sand/liverock or the mud? Seems I've heard some negative comments on the mud setup.
<<Six of one, half a dozen of the other. LR/LS will be less expensive, set up as DSB it will reduce nitrates all the same. LR/LS has various size particles and microenvironments for pods, phytoplankton, etc.
Most DSB experts say oolitic sand is essentially mud. Mud is a description of particle size and the space between the particles.
For maximum diversity, LR rubble of various sizes with a DSB with coarser sand on the top layer would be my choice. IOW, fairly coarse material (aerobic) settling down to very fine particles on the bottom. (anaerobic)>>
Also, the LFS said I should run the lights 24/7 to control the
life cycle of the Caulerpa, to keep it or algae from taking over the big
tank. I don't want to run lights 24/7 for energy reasons and it seems to me the main tank herbivores would control the Caulerpa before it could get established. Your opinion? 
<<The Caulerpa goes in the refugium where it has "refuge" from predation so it can grow. It doesn't go in the main or where there are herbivores. It can be transferred into the main for food, etc, but you grow it in the refugium. You can run the refugium lights (should) on a reverse cycle, IOW, the opposite of your main to stabilize pH. The problem with Caulerpa is it goes through some wasting cycles that are problematic, and can be avoided by the 24 hour cycle, keeps the Caulerpa in grow mode full time. There are other better marine grasses and plants that have fewer negatives than Caulerpa. Search "refugiums" at WWM, lots of info.>> 
Also, the refugium is 48 in by 25 high, perhaps
maintaining a mud system in this size refugium would be a lot of trouble, I would like to go with the most maint free setup. Thanks for your time. Great site. Paul
<<Small differences. I would look into the many other options you have.
All of these will work. There are many considerations, financial, maintenance, habit, etc. Check out more info on WWM, that will help you. Craig>>

Refugium Question
Hello,
<<Hello Cheri>>
Hope you are doing well today! <<Yep, perfect weather, nice sunny day, how can it go wrong?>>
I was hoping you could answer a couple of quick questions for me? I am converting my wet/dry filter over to a refugium and I was not sure of a couple of things. The tank is a 55 gallon reef with a low bio load: 1 sm six line wrasse, 1 sm lawnmower blenny, 1 scooter blenny and two barnacle blennies. I also have approx 85-90 lbs of Fiji live rock and 217 watts of pc lighting:
<<Sounds good. Hope the blennies all get along...little characters!>>
1. Should I remove the final water polishing sponge before the return pump?
<<Yes. Perhaps look into a low sheer pump to preserve as many/much of the pods, etc. as possible so they are pumped up into main.>>
2. Should I still use the drip tray/filter pad or would it be ok to use a piece of filter pad where the water overflows into the center section of the former wet/dry now refugium?
<<Your choice as long as you keep it clean regularly to prevent nutrient production. Good to have some physical filtration removing actual pieces of stuff from the water. I assume the drip tray/filter pad is under tank return to sump? This is good too if it works for you. Hard to tell from here, but they would now perform essentially the same function...physical filtration. Hope this helps with your decisions! Craig>>
Thanks in advance for your response and your great site!!
Cheri

Re: Refugium Question
Hi Again,
Thanks for the speedy response. Do you have any recommendations regarding what type of "low sheer" pump to use? Thanks Cheri
<<There are several co's. Tunze makes them. Try searching WWM or the web. Craig>>