too much & not enough algae

[Jason in Oakland]

I have 5 golden barbs & 2 small otos in a 12 gallon tank (tank fully
cycled, never goes beyond zero for ammonia or nitrites at this point).
When I first set up my tank, I got brown algae (apparently typical in
new tanks) which the otos gobbled up. Then I had little to no algae,
and my otos never took to either the blanched zucchini or even the
algae (Hikari) disks I put in there, but the piggish golden barbs did.
The otos seem to like "vacuuming" the leaves, gravel and tank walls
and nothing else. And they seemed bare.

About a week ago, I went out of town and added some phosphate-based
buffer to increase the algae in my tank, on purpose, to feed the otos.
When I got back, the water was GREEN....one-celled algae organisms. At
this point, I'm worried:
1) the floating one-celled algae are not edible by otos; they need
stationary types of algae
2) the green water algae is using the light and nutrients in the water
that could be used by either the plants in my tank, or the algae that
would grow on them (food for the otos)
3) even with a bubble wand, the algae & its eventual decomposition
would eat up lots of oxygen if I tried the 4 days of darkness for the
tank, and there would be even less for the otos to eat

Few questions:
1) What is an oto-specific food source? The Hikari algae discs have
some krill & other meat sources, so my hungry golden barbs attack it
before the otos even see it. The otos don't seem to like blanched
zucchini or lettuce. Any way to grow stationary algae without causing
a green water algae bloom?

2) How to get rid of the green water with minimum stress to my fish &
specif otos? One of my otos died before, I think either due to
starvation or stress. I don't want to repeat that again. So far, I've
been doing 25% water changes every day, to slowly remove the
phosphorus I added (I think the "fresh nutrients with tap water" is
bunk, unless you have phosphates in your tap water, which is
exceedingly rare nowadays). When I had no phosphates, but some
nitrates (from the nitrogen cycle), my water had no green tinge.

Thanks!
Jason

[Matthew Clark]

> About a week ago, I went out of town and added some phosphate-based
> buffer to increase the algae in my tank, on purpose, to feed the otos.
> When I got back, the water was GREEN....one-celled algae organisms.

Well, I hope you learned your lesson.

> 1) the floating one-celled algae are not edible by otos; they need
> stationary types of algae
> 2) the green water algae is using the light and nutrients in the water
> that could be used by either the plants in my tank, or the algae that
> would grow on them (food for the otos)
> 3) even with a bubble wand, the algae & its eventual decomposition
> would eat up lots of oxygen if I tried the 4 days of darkness for the
> tank, and there would be even less for the otos to eat
>

You know your stuff from a scientific standpoint, but this didn't
translate into common sense (obviously, you shouldn't have added
phosphates). The common sense of fishkeeping will come with time;
excessive resort to chemicals is typical of individuals who generally
speaking know their stuff but haven't been keeping fish long enough to
apply it.

> 1) What is an oto-specific food source? The Hikari algae discs have
> some krill & other meat sources, so my hungry golden barbs attack it
> before the otos even see it. The otos don't seem to like blanched
> zucchini or lettuce. Any way to grow stationary algae without causing
> a green water algae bloom?

Don't worry about feeding otos. You only have two of them, they are
very small, and they should get by just fine on slight amounts of
algal growth that will occur as well as microorganisms that you can't
see.

> 2) How to get rid of the green water with minimum stress to my fish &
> specif otos? One of my otos died before, I think either due to
> starvation or stress. I don't want to repeat that again. So far, I've
> been doing 25% water changes every day, to slowly remove the
> phosphorus I added (I think the "fresh nutrients with tap water" is
> bunk, unless you have phosphates in your tap water, which is
> exceedingly rare nowadays). When I had no phosphates, but some
> nitrates (from the nitrogen cycle), my water had no green tinge.

Keep changing water, feed very sparingly, turn the lights off, and
don't try to cook up an algae for your otos again.

Matthew Clark

[Happy'Cam'per]

> Keep changing water, feed very sparingly, turn the lights off, and
> don't try to cook up an algae for your otos again.
>
> Matthew Clark

LOL@Matthew
My Ottos seem to really enjoy a thin slice of cucumber (raw) every 2 or 3
days. Go nuts for the stuff.
--
**So long, and thanks for all the fish!**