Roger

I have recently started of a Biorb tank and have Guppy and Tetra in it. I noticed yesterday that one of the Guppy was not its normal self, and this morning it is nowhere to be seen. I fear that it may have died, but without completely emptying the tank what should i do? If it has died, do I leave it it and hope it will float to the surface? or what? Can any one help?
Roger.

Blub

What are your water parameters?

Fish don't float to the top when they die - often they sink. The carcass will have either rotted or got trapped in the filter by now.

Roger

If they have rotted, will this affect the water in my tank?

Alessa

also, first you say in your aquarium info, for ammonia nitrite and nitrate "ok" but you also say that you dont know about the nitrogen cycle... so you really know about the cycle? do you know what your exact readings are?

also what kind of tetra do you have? most (if not all) of them are schooling fish (need at least 5 of them). The same with guppies,(need at least three with those) and you cant really fit that many fish in a 30 l. (7.5 gal)

and yes, if they have rotted it will affect the tank water a lot.

Blub

No member of the characin family is not social. Even pirahnas need a school!

In a 7.5gal, a fish rotting is going to add a lot of ammonia!