Marine to Freshwater.   11/14/07
Hello all.
Quick note to great website as ever but am struggling to find my answer so hope you can help.
I have run a largish marine set up (500ltr with 100ltr sump) for 2 years and am finding it difficult to find time for the maintenance. I am considering to go back to a fresh water set up but I want to use the existing equipment. Can you let me know if there are any pitfalls with this.
<Essentially no problems at all. The main thing is that some systems used in marine tanks either won't work in freshwater or won't be helpful. Protein skimmers stop working below about SG 1.010, and things that drive off carbon dioxide (like trickle filters) won't be appreciated by plants (which want all the CO2 you can give them). Lime-rich materials used for decoration are fine in hard water tanks, e.g., with Mbuna, but can't be used in standard aquaria where neutral or acidic environments are desired.>
The sump has miracle mud (though this will be got rid of), bio balls and live rock which is lit. What would you recommend to put in the sump?
<Doesn't matter too much. Anything that will support biological filtration will be fine. So go by your budget or whatever appeals to you.>
I have T5 lighting that alternates with a 'moon' light for the night time. Would this be ok or too much.
<Depends on what sort of fish you are keeping. Some freshwater fish don't like bright light (e.g., Discus). But if you have lots of plants to provide shade, strong lighting is useful. Among other benefits, rapid plant growth suppresses algae and consumes nitrate. Floating plants like Ceratopteris are especially good for this.>
I would replace the substrate from fine marine sand to normal gravel (or would you leave alone?).
<Depends on the fish. Coral sand or lime-rich sand are fine for hard water tanks. But if you keeping a planted aquarium you need particular iron-rich, slightly dysaerobic substrates for them, and standard community fish wanting a neutral pH need an inert substrate such as silica sand or gravel. So research your stock list and planting ideas, and choose substrate based on that.>
Any other problems I might encounter?
<None that can't be prevented by research! On the whole, if you've mastered marine fishkeeping, freshwater fishkeeping should present too many problems. The common mistakes -- overstocking, overfeeding, inadequate filtration, etc. -- are identical. Live plants present peculiar problems similar to but different from those of corals. They need light, yes, but they also need CO2 and a nutrient-rich substrate (unless the plants kept are floating plants or epiphytes, in which case substrate is irrelevant). The range of invertebrates is more limited, primarily shrimps and snails, but by contrast with marine tanks, freshwater invertebrates tend to be easy to keep and prone to overpopulation if not watched (I have cherry shrimps breeding at a rate that would make me a billionaire if they were marine cleaner shrimps!). The main difference is really one of specialisation: while virtually all ornamental marine fish are from coral reefs, freshwater fish come from a range of habitats from mountain rapids to swamps to giant lakes to rainforest rivers. All require different sets of conditions. Much of the fun in freshwater fishkeeping comes from specialising in one particular habitat, and collecting fishes and plants typical of that habitat. You can then choose rocks, sand, bogwood and other decorative materials to create the "look" of that place, too. Water-worn boulders and Vallisneria would suggest a fast-flowing Asian river, while Anubias and bogwood roots could be use to create an African swamp. And so on. There are several books out there all about this aspect of the hobby. My favourite is 'The Complete Aquarium' by Peter Scott.>
It the moment I have a 10 times water flow. Is that too much for fresh water, should I just use the return pump from the sump (3500ltrs p/h).
<My freshwater tank has a similar turnover. It presents no problems to riverine fish that like water current, things like Corydoras, pufferfish, Plecs, midwater barbs and tetras, etc.>
Many thanks for any pointers.
Paul
<I hope this helps, Neale>

Saltwater to Freshwater   5/18/07
Hi folks, great site!
<Hello Billy.>
I recently purchased a used 55 gallon saltwater tank that I want to use as a freshwater tank. It's your standard 55, 48x12.5x18 (or close, you get the idea). It has 2 Emperor 400 BioWheel Hobs and a Rena XP2 canister. I already removed the crushed coral. The plan is one or two Oscars (I know 55 is pushing it) and a pleco.
<Sounds fine so far, though as you seem to realise, all these fish, if not actually huge, are messy, and tend to make small tanks with basic filtration rather murky.>
This is the reason I was happy about the amount of filtration. In this area there is one person at one LFS that seems to know some things, and he's hard to catch. Other than that, you have your basic retail help. Very eager to help, just no experience. That's why I came to you guys.
<Or better yet, invest in a good aquarium book. There are titles at every price point, and sitting down and reading is time well spent. Your public library will also have a variety if you don't want to buy a book.>
I have a few questions about what to do next to convert the tank to freshwater: Will a good rinsing of the tank be sufficient?
<Yes. Very few life forms of any kind, beneficial or otherwise, will survive going from marine to freshwater conditions (that's what makes brackish water animals so special). Almost all the bacteria, algae, potential pathogens, etc. will be killed merely by changing the salinity. Throw in a good clean with warm water and a sponge, and you're laughing.>
It's actually soaking in the garage now to see if there are any leaks.
<Good call.>
What about the HOB filters, same?
<Yes. Obviously you'll need to re-cycle the filter to get the bacteria back.>
I've never used a canister. Is inside the stand, under the tank, ok?
<Standard place to put it. BUT, because it is now working against gravity, pushing the water up from the filter into the tank, the pump moves less water. So knock off at least 25% from the stated turnover of the filter to allow for this and a certain amount of clogged filter media.>
What if I lose power, will gravity pull the water out of the tank and onto the floor?
<Not if you've connected it properly. Switching off the filter will simply stop the water moving. Nothing should leak out. A couple of tips though: Make sure there's a drip loop on the power cable, i.e., the lowest part of the cable between the filter and the power outlet is LOWER than the power outlet, so any dribbling water goes onto the floor not into your mains electrical supply. Secondly, if you're paranoid about leaking water, drill a small hole on the INLET tube in the aquarium an inch or two below the surface of the aquarium. What this will do is break the siphon if a leak develops in the canister filter system, so only the first one or two inches of water can escape from the tank. Any good aquarium book should show you these two tricks.>
And same as before, will a thorough rinsing be adequate? What goes
into the 2 baskets inside? Any words of wisdom for a nervous canister newbie?
<Here's Neale's golden rules of canister filters. [1] Don't use carbon, zeolite, or peat. All three are unnecessary in most freshwater aquaria. [2] Choose a mix of mechanical filter media and biological filter media. [3] Filter wool is excellent for mechanical filtration but needs to be replaced periodically. [4] Good quality sponges or ceramic media are well worth buying because they last for many years. [5] Do a trial run setting up the canister filter with a bucket of water in the back garden or in a sink. The first time you use one you'll find them fiddly, so it's worth figuring out the rubber seals and various taps somewhere an accidental leak won't do any harm. [6] Once set up, leave the filter alone. You only need to clean it very occasionally, certainly no more often than once a month, and some aquarists get by cleaning them once a year. It'll be obvious when water flow is declining, and that's when to clean the filter. [7] If your filter is clogging up within weeks, it's overwhelmed. Either add a second filter, or be more proactive with the hosepipe and bucket, siphoning out detritus on a daily basis if required (this is what I do with my tank with an adult Panaque who could poop for Britain if it was an Olympic sport). [8] Never, ever clean the filter media in anything other than fish tank water.>
My plan was to run the filters for a while in the sink to flush them out.
<Seems a bit pointless but okay.>
It didn't come with any actual inserts (media?), so those will be new anyway, but the tubes, impellers, and are where the filter inserts hang would get a good flushing.
<Some filters come with media, some without. Hardly matters really some these are low cost, long lifespan purchases. A box of good quality filter media like Siporax will last ten years or more if looked after properly.>
Thanks in advance for any and all help!!!!
Billy
<No problems. Good luck! Neale>

Marine to freshwater conversion   1/6/07
<<Hello, Jonathan. Tom here.>>
I have a 90 gallon FOWLR with a DSB (4” of aragonite sand), 10 gallon
refugium, 20 gallon sump, and a closed loop manifold that gives me about 18X circulation rate when I combine the sump return pump.  
<<Okay.>>
I was always a freshwater keeper but last year built this marine setup and have found myself recently wanting to switch back to the freshwater world. How difficult would it be to switch this setup to freshwater?  
<<With a few changes, I don’t see this as being a problem at all, Jonathan.>>
I understand that the live rock, skimmer, and algae in the refugium would have to go with the fish, but what about the substrate?  
<<The aragonite sand would likely be one of the changes you’d have to make unless you intend to keep species requiring a high pH – in the 8.0+ range, African Rift Lake Cichlids, perhaps. Because of the sand’s constant release of carbonate into the water, you’ll never get the pH down below what is commonly reserved for FOWLR and reef setups.>>
I am interested in a planted tank. Could I pull the substrate and rinse it thoroughly?
<<We’re still at the issue of pH here, Jonathan. No amount of rinsing will change the sand’s natural characteristics. Additionally, this rules out my earlier reference to the Rift Cichlids. Plants won’t last a half hour.>>
Is the 18X turnover rate too much for a planted setup?  
<<I would say so. You probably wouldn’t want to exceed 12X with a planted tank and even this depends on what types of plants you want to keep.>>
Could I find some beneficial use for the refugium?  
<<Depends on how closely you want to stick with the inherent use for a refugium. As you know, these are often used for inverts and delicate species that wouldn’t survive in the display tank due to something trying to make lunch of them. Might take some imagination on your part but I wouldn’t rule out the possibility of making use of it in a freshwater application. Obviously, since the display and refugium would have identical water parameters, your selections would have to be made accordingly.>>
I am only testing the waters, y’all have always been very helpful before.  Thanks for your advice.
<<All in all, I don’t see this as a bad way to go, Jonathan. It’s been quite a while but I spoke with a fellow who laid out a large FW system almost identical to what I picture yours to be. Can’t say I recall what his use for the refugium was, unfortunately, but equipment-wise, all he, understandably, lacked was a protein skimmer. All else was a “saltwater” setup with the exception, of course, of the inhabitants and salt.>>
Jonathan
<<Good luck with the conversion. I’d be interested in finding out how you go with this. Tom>>