School sizes for 20 gallon tank

[sdrone]

I've got a 20 gallon (tall) tank with sand.

I've currently got a rather large orange gourami (4' or more) that the kids like, 2 silver dollar fish, and a pleco that's 4 to 5 inches long. I've found a local store that will take "donations." The corporate stores won't. So I'm considering "donating" the pleco and the 2 silver dollar fish.

I need some tank cleaners, and I'd like a middle or top of the tank fish. One of my daughters has decided she loves black mollies. Would 4 cory catfish, 4 black mollies, and the orange gourami ("Ursula" since she has tentacles) be too much for a tank this size? I'm not really sure how many of each type to get; I've read that mollies and cories do better in schools.

I wanted some shrimp, but I think I'll be putting that off for a few months.

 

[XimeD]

I have only been in this hobby for 4 months and have no experience with the group of fish you want to keep, but here is a website I like to use to give me a general idea about stocking:

AqAdvisor - Intelligent Freshwater Tropical Fish Aquarium Stocking Calculator and Aquarium Tank/Filter Advisor

A lot of experienced people on this forum don't like this site because it is VERY conservative in its estimates (ie having a tank stocked at 150% or more according to aq with no issues whatsoever) Having said that, I take everything there with a grain of salt but I feel it's a good site for people just starting in this to get a "feel" for stocking.

Cheers,

 

[ilovemydragongoby]

mollies aren't actually a schooling fish. but if you're getting more than one you need a gender ratio i think its three females to one male. other wise the males will just pick on the female constantly. and you would have to be prepared for the fry explosions. i had 15 mollies in my 80 gal tank and i had ruffly 30 fry every 2 weeks.
i dont know much about corries, why don't you try otos? i have 3 of them in my 55 as a "clean up crew" with my ghost knife. they're really fun to watch they do play together.

 

[sdrone]

Well I'm always open to suggestions. Will they scavenge food off the bottom? Or are they strictly algae eaters?

 

[TheCrazyFishLady]

Corys can be fine on their own if there are other active fish around, but they are much, much happier in a group. I have three together and they play for hours. I am not the most experienced, but I think it sounds good.

 

[Gus]

To keep the bottom clean, I have 4-5 ghost shrimp, and they do a good job picking up little pieces of food left over. For schooling, I added 5 Rasboras to my 10 gal tank, and I'll tell you, I'm thinking in getting a bigger tank so I can add more! They are always together swimming all over the place!

 

[Bigzmey]

I've got a 20 gallon (tall) tank with sand.

I've currently got a rather large orange gourami (4' or more) that the kids like, 2 silver dollar fish, and a pleco that's 4 to 5 inches long. I've found a local store that will take "donations." The corporate stores won't. So I'm considering "donating" the pleco and the 2 silver dollar fish.

I need some tank cleaners, and I'd like a middle or top of the tank fish. One of my daughters has decided she loves black mollies. Would 4 cory catfish, 4 black mollies, and the orange gourami ("Ursula" since she has tentacles) be too much for a tank this size? I'm not really sure how many of each type to get; I've read that mollies and cories do better in schools.

I wanted some shrimp, but I think I'll be putting that off for a few months.

Mollies are great choice if you need top/middle tank fish. You don't have to get 4. You may just get a couple of females. Males are hit and miss, some of them may be quite aggressive. If you get 3 females/1 male be prepared to deal with lots of babies. Mollies are quite entertaining,they would eat food at all water levels and will clean the floor, but not as effectively as corries. Corries are fun as well, but they are mostly bottom feeders and are good at that. You would need to feed some sinking pellets, don't expect them do well just of leftovers. Actually, mollies love sinking pellets to so your 4 cory catfish, 4 black (female) mollies, and the orange gourami combination should work just fine.

 

[sdrone]

Thanks for the info, everyone.

Will corys eat algae tablets? I've been using those to feed the pleco.

 

[Bigzmey]

Thanks for the info, everyone.

Will corys eat algae tablets? I've been using those to feed the pleco.

Yes, they love them.

 

[sdrone]

My daughters and I took my wife by the local pet store, just to get clearance from the tower so to speak.

She wasn't thrilled about the black mollies my older daughter had picked. The daughters were so distracted by everything else in the store that they weren't much help picking alternatives.

My wife wanted something more colorful; guess black isn't considered colorful. She did like the tiger barbs, which I'd tried to sell the girls on.

So, now I'm thinking a school of 5 tiger barbs, maybe 3 cory catfish, and the original big orange gourami.

The elmer's aquarium link in the stick thread about choosing fish recommends aquarium salt for the barbs as well. The aquarium seems to be pretty stable, though I'm probably still overfeeding a bit, and I can't seem to get the ammonia to zero. The yellow always looks between zero and 0.25.

 

[Jason7894561230]

The thing about tiger barbs are that they are fin nippers and will have ago at your mollies and cories

 

[sdrone]

There won't be any mollies. I was hoping since the cories are active and mostly at the bottom of the tank, that could be avoided. Are tehre bottom scavengers that would avoid this issue?

 

[sdrone]

I ended up picking up 3 cories and 4 tiger barbs. I figured if there were a problem I'd pick up another tiger barb in a few days.

At this point, the only problems seems to be that the tiger barbs are spending most of their time at the bottom of the tank, whatever corner is exactly opposite the gold gourami. They didn't go to the top to feed, but did fight over the algae tablet I dropped in for the catfish.

I'll have to see how everyone gets along in the next few days. The gourami and barbs did exchange a few nips this afternoon.

 

[Bigzmey]

mollies come in many colors: black, orange, yellow, white. You may also consider platies, they are quite colorful.

 

[Vircomore]

Also, if you're looking for algae-grazers or tank-cleaners, don't think that you're limited to fish.

Like others suggested, you could consider getting either shrimp, or perhaps some Freshwater Nerite Snails. They may not be all that exciting, but they get the job done and they won't become an infestation.

 

[sdrone]

Sure - and I hope to get some shrimp on the future.

At this point, I'm done with changes to the aquarium for a while, after removing 3 fish and adding 7 yesterday. The only change I'll make in the very near future is to perhaps add another tiger barb to bring the school up to 5.

The gourami chased the barbs yesterday and last night, and the barbs are mostly staying at the bottom of the tank, but who knows - I'll give that a few days to shake out.

I'll keep it stable until later this month when I stop running on 2 filters by getting rid of the filter that came with the aquarium and just run on the Aquaclear, pull out the panty hose full of gravel from the old aquarium, etc.

 

[Coleallensmom]

Also, if you're looking for algae-grazers or tank-cleaners, don't think that you're limited to fish.

Like others suggested, you could consider getting either shrimp, or perhaps some Freshwater Nerite Snails. They may not be all that exciting, but they get the job done and they won't become an infestation.

I actually enjoy my nerites! I have three Zebra snails and every morning one of the first things I do is check to see where each of them are...they are quite the little movers!