Need help with fixing compatibility in our 15g

[MrsFroshinator]

We have recently stocked our 10gallon with the Glowlight Danios. Originally this was to be my 5year old's "pet" and has turned into my job rather quickly. I'm having trouble keeping these fish alive and fins intact.

Our tank currently consists of 5 Glowlight Danios, 5 Glowlight Tetras, and 1 Neon Tetra (there used to be more, and the one little guy has been doing rather well with the rest of the fish).

I have had our water tested several times and its always exactly where it should be. I've woken up several mornings to find fin-less fish stuck in the filter. The tank is right next to my desk and so I am constantly trying to see which fish are doing this. Is there something I should be doing that I'm not? Are these fish just not compatible? I currently have one Glowlight Danio that I hope is going to make it, since it is currently missing its caudal fin.

[mizzoutank]

What are your water parameters? ammonia/nitrite/nitrate?

Danios can get nippy, especially when not given proper room to swim. they are very active swimmers and need long spaces to swim.

do you notice any aggression during feeding/nighttime/daytime?

what is the current filtration?

[MrsFroshinator]

I'm going to be honest with you and say I really don't know the exact numbers. Ive taken water samples to the store and they test it for me. I have the test strips but am not sure what the water should be.

I don't ever notice aggression, so I'm assuming it happens when we're sleeping and all the lights are out. The danios are always fast to eat but never really bother the others.

The filter that we are using is an Aqueon 20. The tank is clean and never cloudy. The temperature is set at 78 degrees.

Could I just have aggressive danios? Should I take the tetras back and just get a couple more Danios? None of the danios have died, but I do have one that has a bitten off fin (though I have no way of knowing which fish did it.)

Thanks!

[imma24]

Honestly? The danios don't really belong in a 10gal tank - they need a lot of swimming space (length-wise) and don't stay very small (I'm sure you have baby fish).

It's in your best interest to get yourself a good liquid test kit instead of using test strips (we usually recommend the API freshwater) - what do you mean by your parameters are "always where they should be"? Does this mean the pet store dips a strip and tells you "your water is fine"? They (the strips) aren't accurate. It appears you are in the middle of "cycling" (going through the nitrogen cycle) your tank - if you want to do what's best for the fish in the tank you will need to keep on top of the water parameters yourself so you know exactly how high your readings for ammonia, nitrites & nitrates are - those readings will tell you how often and how much water to change in your tank. A cycled tank shows 0 for ammonia & nitrites, 20 or less for nitrates (NOT zeros for everything).

If I were you, in addition to getting a liquid test kit, I would return the danios & the neon & get more glowlights as they are schooling fish & are appropriate for that sized tank - a few more would make them happier - but 1st, once you return the danios, I would make sure the tank is cycled (there is an article in the beginners section you can read) before getting more fish.