Advice on fish school densities

Jul 22, 2016
Hello! I am new to the wonderful world of aquariums!

I recently purchased a 10 gallon tank and am in the process of cycling it (I had originally thought I'd purchase a smaller tank as I live in a small apartment, but doing some research I decided that 10 gallons was the smallest tank I can humanly keep fish in).

I have my heart set on eventually purchasing GloFish Tetras, but want some advice on the appropriate density so that they aren't stressed that their school is too small and still have sufficient space. I also plan on getting a few snails to help keep the system in balance.

In your experience, what is the proper number of both Tetras and snails to help keep the tank and fish happy and healthy?

As a side question - do you have any advice on what to do when your water is too warm? Its been quite a warm summer and my thermometer is reading water temps between 80 and 90 degrees... and I fear with August around the corner the worst is yet to come. My heater is plugged but seems to be accurately reading the temp and NOT turning on. Normally I'd be all too happy to just wait an extra month to purchase fish until cooler weather sets in, but I think that's just delaying the inevitable - I'll probably be dealing with this same issue again in 12 months. Do I drop an ice cube or two in before leaving for work and hope that's sufficient until I get home 10 hours later? (I'm a bit of a work-a-holic)


The Big Fish
The Big Fish
Oct 22, 2002
Sunny Southern California
welcome to MFT!

to deal with the heat, i've seen people take water bottles. freeze them and then float them in the tank. it acts basically like a giant icecube. but you'll need to monitor the temperature to make sure it doesn't drop too quickly or too much.

tetras are schooling fish so i usually like to keep them in groups of 5. i think 5 would be okay for your tank. but it'll depend on how much you feed and how often you change the water.

Jul 4, 2016
Hello, please don't put glo fish or neons in, they need at least 5+ and are not for a ten. Neons need a 15+, danios need a 20+. If you want a schooling fish, you could get ember tetras. Bettas are probably your best bet, perhaps delicate blue eyed rainbowfish(I don't know their temp, check seriously fish). If you split the tank you could have two Bettas. What's your temp without the heater? There are cooling fans that you can use and as stated above you can use frozen water bottles or zip lock bags of ice. Just make sure to rinse everything off before you place it into the tank without soap.