Outwitting Silver Dollars with refug./sump

[julianop]

Thanks in advance for help on this problem...
Information:
My two silver dollars eat everything I plant in my 29g. of course, and I have a nitrates/algae problem, of course. Letting the little rascals go to another home is, of course, out of the question: they've been with me so long I couldn't even guess how old they are.
Though it has seen better days, the tank is currently only lightly loaded with the s.d.s, a pair of clown loaches and a couple of hatchets, and heavily filtered with a Fluval canister filter (a.k.a. nitrate accumulator!) running full time as the only continuous circulation/treatment (the stack has two levels of bio and one of carbon). The tank has an old Marineland hood with a pair of fluorescent tubes for lighting, and I run the hood's filter/biowheel periodically by means of a timer, but my wife doesn't like the noise, so when she's watching telly in the evenings it runs only for a few minutes every hour to keep the wheel wet. The tank has a shallow gravel substrate, no ugf.
I don't have a lot of time for maintenance, but don't want to give up and tear the tank down, and instead would really like it to see some glory, so before I restock it I need to be able to plant something (and/or take other measures) to keep nitrates & algae under control and improve water quality.
SO... I have just begun to try and beat back the green and brown algae by setting up a cheap 5.5g with LED lights as a refugium with some plant cuttings in it. The refugium is on a convenient shelf beside the main tank, connected via a siphon link, such that the water surface in the main tank is half way up the refug. The water levels are therefore equal and safe under no-flow/power-out conditions. I put an old Penguin 550 powerhead in the main tank (improving flow, which can't hurt), and water is drawn from the refug. into the main tank using what would normally be the aerator input on the output of the powerhead. Flow back into the refug. is via the 1/2" i.d. siphon pipe. The nice thing about this setup is that if the siphon breaks the draw from the powerhead is nowhere near powerful enough to evacuate the refug. The flow isn't great, but I believe it's enough to feed the plants.
I'd like to put a real planted refugium under the main tank, but there is precious little room, and as stated/ implied, I can't add more noise to the system. I plan to add some more plants - some emergent and some floaters - and a cutting of Pothos.
Question:
What else could I do, either with or to this makeshift refugium, or to my setup in general, to help keep the nitrates & algae under control and improve my water quality?
Thanks again, in advance, for your creative input!

 

[tanker]

I would not call a 29gal lightly loaded if it has " s.d.s, a pair of clown loaches and a couple of hatchets".
IMO, you will not be able to keep any plants with SDs.

 

[julianop]

I guess I wasn't clear: I'm putting the plants in the extra tank, not in the main tank; that's the whole point of having it.
The two silver dollars are less than 4" each, the loaches 4" each, maybe a tiny bit more, and the hatches are two inches between them.
You're saying that eighteen inches of fish in 29 gallons isn't lightly loaded? That doesn't come anywhere near 1" per gallon by the volume method, and using the surface area rule of 12 square inches per inch of fish, with a 30x12 area we're still talking 30" of fish.
What am I missing?

 

[Rbishop]

The 1" of fish per gallon is a pretty obsolete guideline (as is the surface area thumb rule). At most, you can use it for small when adult, slim bodied fish and that is it. It doesn't even begin to account for personality and eventual size, nor territory issues as well as schooling traits and space to swim. Either of those would say it's okay for a 24" fish to be kept there.

I also believe, the term nitrate accumulator is meaningless. Any tank accumulates nitrates, it's part of the cycle from ammonia to nitrite to nitrate. It's going to happen. We get rid of nitrates by WCs or with plants that consume them. WCs do more than reduce nitrates though, they also replenish other minerals that we don't test for.

 

[FreshyFresh]

Julian, we are definitely saying silver dollars and clown loaches of any number or length is too much of a bio load for a 29g tank. The footprint of a 29g is also not appropriate for the activity level of these fish. It's worked for you up to this point, but I'm not surprised you're battling algae or water quality issues. Lots of filtration and clear water doesn't mean it's healthy water for fish.

Could you keep good water parameters with these fish in a 29? Absolutely, but it would probably require several large (75%+) water changes per week.

Your refugium/sump with plants can help some, but the only real solution is lots more water changes. If you can't do this, I'd move the clown loaches to their own tank (55g maybe) and just leave the pair of SDs in the 29g.

 

[julianop]

Thank you all for your wisdom, advice and clarification on this issue! I'll purge those old guidelines from my thinking.
It has been clear to me for a while that a larger footprint would certainly benefit everybody in the tank, but I didn't know about the higher bio load needs; that certainly explains my problems.
A bigger tank is going to be a challenge in terms of both cost and domestic space (even as a replacement, never mind as an addition!), but I'll certainly commit to doing so: these are my pets, and I don't take the responsibility lightly (that's why I'm here). I'll certainly increase WC ratio & frequency in the meantime.
On that subject, I have an RO unit I used to generate water for a small FOWLER marine setup I no longer run (time constraints again); I've heard some folk talk about an RO/de-clorinated tapwater mix; would that be adviseable, or not?
More questions, if you don't mind...
What size would you recommend if I want to keep the SD's and the loaches in the same tank?
Also, given the bio load and the incompatibility of SDs' and plants, would you suggest I upgrade the planted sump idea to a more powerful unit with additional multi-stage filtering and decent lighting to augment the Fluval?
Thanks again. I'm glad to have found a source of experience and sound advice.

 

[Rbishop]

RO/tap mix for freshwater is usually done to bring unacceptable tap conditions to more normal requirements. Such as high nitrates, ammonia, pH, or GH/KH straight from it.

For me, the clowns need at least a 6' length tank and preferably a group of 6 or more. They are also slow growers, active when thriving and can be skittish at times, earning their tank buster nick names.

 

[julianop]

Thanks for that clarification on the RO water, RBishop. I'm in Minnesota, and my tap water has fairly high GH (around 160mg/l) otherwise not bad. pH is around 7.4.
I have no idea how I'm going to provide 6ft of tank length :-(

 

[Rbishop]

You could easily get away with a four footer for a few years.

 

[julianop]

That might be possible...
What would be the typical life expectancy for SDs and loaches? I'd say these are a good five years old already.