I am pretty new to the fishy world, so I don't know a whole lot. Sorry if this question sounds dumb. My tank has been running well for a little over a week now, and it's going great. I have noticed that the water levels are getting low due to evap ( I live in a desert). I need to add mroe water, adn I know it should be conditioned, but that is the problem. How much conditioner do i add? It is only a 10gal tank, so I don't need to replace a lot of water (it doesn't need to be changed yet). The instrucations say add 5ml of conditioner to every 10gal, but I don't need to refill the whole tank! Do I calculate how much conditioner I should use per gal, or do I still add a whole 5ml? I'm so confused!

The amount of conditioner you add would depend on the amount of water you are replacing. You would want to calculate the number of gallons you are replacing and add half a ml for each gallon. How far from the top of the tank is the water now? If it evaporates like my tanks, you would want to use just a few drops for the new water.

Keep in mind when the water evaporates, it leaves behind the minerals, salts, metals, etc. Be sure to make regular water changes so they do not build up to toxic levels.