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Too much light for low tech 20 gallon?

1654 Views 5 Replies 4 Participants Last post by  zergling
I am planning on a 20 gallon low tech tank project. Is 55 watts (ahsupply) to much for my low tech tank? No co2 but maybe excel occasionally. Ferts will be apply weekly.
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I doubt it. I run 55w over my 25g low-tech that's only dosed with Excel and the plants are doing decently. Most importantly, there's very little algae, save a little bit of clado.
If you only let the lights run for 8-9 hrs, you'll probably be better off. I run mine for about 8 hrs / day.
Great! Just wondering what you are growing in there?
55w would be 2.75w/g, so it would be moderate high lighting. i think you'd have to go with co2 or consistent dosing of excel and maybe use ei.

i have a 20h with a 36w ahs on it (1.8w/g); photoperiod is 8 hours. i have pressurized co2 and dose ei. i grow "high light" plants such as limnophila aromatica, hemianthus micranthemoides, glossostigma elatinoides , and cardamine lysrata and "low light" plants including anubias barteri 'petite' and microsorum pteropus. all plants are thriving. battling some bba, but i put my bba mower (rosey barb) in recently and he's going at it.

alright have to rethink my lighting options here.... tom barr always say less light is better so 36 watts it is.... cheaper too
It's hard to say if a 55W kit from ahsupply is too much for a 20g long low-tech tank (no, I do not follow this watts per gallon concept), because it's quite easy to lift/lower the kit from the tank to increase/decrease intensity.

I'm concerned about coverage though. The kit is only 22" long, so even if you center the bulb, you're looking at about 4" unlit areas at both ends, but it might still get covered enough if you raise the bulbs enough.

You can look into trying into trying the 24" T5HO retrofits with individual parabolic reflectors. Same deal with the ahsupply kit, but it has slightly better coverage being 2" longer, and you get less light lost through restrike because of the individual reflectors, but good T5HO kits/fixtures are always much more expensive.

I'll be setting 15g tanks (24"x12"x12"; same as 20g long, only 6" shorter) tonight with a single 24W T5HO bulb with parabolic reflectors, one bulb for each tank. I'm quite confident that should be enough for a low-tech tank, so I'll be able to tell for sure after a few months.
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