Water is greenish (see pic) & Oto cat question

[j250nyahweh]

This is a 20gallon long with double filtration kept to 80 degrees. nitrates 20, nitrites .5, hardness 75, alkalinity 80, pH 6.8.

The tank has 5 oto cats, 2 golden plecos and a dwarf puffer
(see http://www.aquaticcommunity.com/aqua...ad.php?t=86811 for puffer fin nipping question)

I don't know what could be causing the green tint. I think it looks kind of cool, but obviously not cool enough if theres any potential harm it could cause.

Next question, we've been trying not to put too many algae discs in the tank thinking that may be part of the cause for the green tint (with no scientific backing whatsoever) but now I'm concnered our oto's aren't getting enough food as some of them are looking rather slender. We do one to two algae discs a day (they are about an inch in diameter). Brine shrimp, frozen blood worms and live black worms get dropped in there aswell. Are they getting enough to eat? Do we need to do more algae discs or anything else?

Thanks for the help!

[hyp0r]

The green color is fine. As long as the parameters are good. Nitrites should be reading 0, not 0.5.

Brine shrimp, frozen blood worms and live black worms are not part of an otos diet. I'm sure they might eat those things if there's nothing else, but really their diet is algae only. I don't use wafers and my oto seems perfectly happy just eating the algae off of the driftwood, rocks and plants in the tank.

[Lady Hobbs]

Ammonia reading is very important. With nitrites showing, you do not have a cycled tank so the ammonia number is really needed. It could be anything.

[j250nyahweh]

The blood worms, brine shrimp and black worms are for the other fish (puffer and before him a gourami) and I thought the same thing about the algae naturally growing in the tank, that it would be enough, but 3 of our 5 otos are looking malourished. There's rarely, if ever, any algae on the glass but it's for sure there on the decor.

The tank should be fully cycled. It's been in it's current state for a few months and was upgraded from a fully cycled (at least 6 months) 5 gallon tank that housed a gourami, then 2 golden plecos and two ghost shrimp for about a month before the upgrade, and we used the old media in the new filter to get the beneficial bacteria. (how's that for a run-on sentence)

Other than the few scrawney otos the rest of the tank seems perfectly happy though, I'll test it all again tonight. Did a partial water changed last night and didn't test it after.

thanks!

[dizzydezzy]

Back when I was considering otos, I was told that they can be a bit finniky about what they eat as all otos you buy are wild caught. Apparently most do best on natural algae (but you need at least 10 gallons of "tank" per oto to sustain them without additional food).

Have you tried feeding zuchinni or cucumber slices instead of the algae disks? Some otos prefer the veggies to the processed foods.. You could also grow some extra algae by putting some rocks in water (in a bucket or similar container) in a sunny spot for a few weeks, and then transfering the algae-covered rocks into the tank for the otos to clean up.

[ldoerr]

I have herd that you should feed vegies to your otos.