CO2 on fish?

[isaac newton]

Could u give me a estimation on my kh???? I have onyx sand for a substrate

 

[djlen]

Estimating kH is a dangerous thing to do, especially in a 10 gallon tank. Due to the small size, a 10 is really susceptible to change in water conditions especially when adding something like CO2. I suggest you find a LFS that does have a kH test kit. It's important that you know certain parameters of your water. Tetra Test makes a master kit which contains test kits for pH, kH, Ammonia, Nitrites, gH(general hardness) and Nitrates. Many of these will be usefull to you down the road and if you buy them all -in-one you'll save quite a bit of cash.
Len