How many more fish can I add to my tank?

[gentledental4u]

Hey all, I have a moderately planted 40 gallon.

Right now, I've got 11 neon tetras, 5 silver hatchetfish, 7 espei rasboras, 2 oto's, 3 sae's and 4 panda corys.

I want to add neon rainbowfish and zebra danios. What do you think? How many can I add if I want just neon rainbows, just zebra danios, or a combo of both.

Spiritwind, I expect you to weigh in on this

[lauraleellbp]

IMO go with one school, either rainbows or danios. They'll show off much better, and rainbows in particular prefer to be in larger schools.

I'd say 10 danios or 6 rainbows.

[Spiritwind]

Well if I must! I would have to agree it is pretty full already, one group is best. The SAEs are taking up a good amount of space, or will when they are full grown. Otos like to have more buddies as well, I think maybe 6 of them makes for a good group. You are gonna have to keep up on the water quality for this fish load with those regular partial water changes.

[lauraleellbp]

x2 on PWC. That recommendation was assuming weekly 50% PWC as with EI dosing... I probably should be careful with that assumption...

[gentledental4u]

Hey all, thanks for your advice.

lauraleellbp, I'm leaning towards getting 6 rainbows. Say, 3 males and 3 females, perhaps? or 2 males, 4 females?

Spiritwind, Yea, the Oto's. I originally had 3. 1 died. Out of all the fish that I've introduced into the tank, the only one that died was the oto. IME, they've been real weaklings, despite my best efforts. The two are fine, but I don't want to get anymore for fear of losing some. One is male (really small) and the other one is a female (she's a real fatty, filled up with eggs). I've heard of them breeding in captivity...who knows? Maybe I'll end up with more than 6! But then again, I've got MTS...they'd prolly eat all the eggs before they hatch.

[gentledental4u]

Originally Posted by lauraleellbp

x2 on PWC. That recommendation was assuming weekly 50% PWC as with EI dosing... I probably should be careful with that assumption...

Yes, this time, you would be correct on your assumption. I'm doing 50% PWC once a week with EI dosing. Plants love it!! They pearl like crazy afterwards!!! Never knew why though..

[lauraleellbp]

2m, 4f

"Never knew why" as in you do now but didn't used to?

FWIW, plants "pearl" bubbles of oxygen. Plants produce O2 as a byproduct of photosynthesis. Underwater, this gas forms into bubbles until the bubble grows big enough to break free of the plant and float to the surface. This is called "pearling," and is a good sign of healthy, happy plants.

[Spiritwind]

Its typical of otos to die early in a tank, if they survive a month they tend to last years. I have read its the way they are caught in the wild. And that they have some special digestion bacteria, and if they are fed poorly in the shop that bacteria dies off and basically they are just waiting to die from that point. This is a fish I bought from Petsmart because they take back fish that die.

[gentledental4u]

Originally Posted by lauraleellbp

2m, 4f

"Never knew why" as in you do now but didn't used to?

FWIW, plants "pearl" bubbles of oxygen. Plants produce O2 as a byproduct of photosynthesis. Underwater, this gas forms into bubbles until the bubble grows big enough to break free of the plant and float to the surface. This is called "pearling," and is a good sign of healthy, happy plants.

Hey, laura, thanks for the explanation. Yea, I get that part. The part that I never understood was that after every water change, they bubble even more. I'm guessing because fresh water is saturated with O2????

[lauraleellbp]

That, plus the surface agitation brings in more- you got it, the water column gets totally saturated.

[gentledental4u]

Thanks!! Totally Rad.

As a side note, 2 of my neon tetras are spawning in my ludwigia repens.

[lauraleellbp]

Wow, congrats- that's actually not a very common thing!

Are you going to try and raise the eggs?

[gentledental4u]

Thanks, they started doing it after I introduced pressurized CO2, prolly lowering the pH and getting them in the mood.

Nah, I think it'd be too much trouble to raise the eggs. I just think it's fun to see them whapping each other's bodies..and seeing the male lead the female to where he wants her to be and then giving her a body whap.

QUESTION: If I get 2 male rainbows, will the dominant male bully the weaker one? that's what I was worried about and why I suggested 3 males.

[lauraleellbp]

That is a possiblity; I looked at your tank size before recommending 2 males, and 40gal pretty heavily planted sounded to me like enough room for one to get away from the other... I've never actually kept dwarf rainbows, though, so you might want to do a little more HW on that one to be on the safe side. Maybe the Fish Profiles on here will give you some more insight, or www.FishBase.org may link you to another site with more info yet.

[TheXman]

Dwarf neon rainbows (Melanotaenia praecox) are pretty tame, two males with four females works pretty well, so would 3 and 3, or 3 and 4. Rainbows in general don't do much bullying. Praecox are on the milder side compared to even other rainbows. They will spar, display, and chase each other frequently, but nothing that really causes much stress unless you have say 3 males and 1 female, then the female never gets any rest from her randy suitors, and that will cause stress, so make sure that the males don't outnumber the females and you'll be OK.