white fuzzy stuff

Question
I have a 2 1/2 gallon tank with  3 guppies and an algae eater. it has a whisper filter and i place an air stone and tube in the tank. i don't normally change the water i replace it when it evaporates every week or so. and the tank is only 8 months old.   i have this white stuff that keeps growing on the bottom.  the fish are still lively and don't seem sickly but i can't get this stuff to go away.  i have tried taking the tank apart and cleaning the whole thing but it keeps coming back.it showed up 2 or 3 months ago when one of my guppies up and died. i replaced him after i cleaned the tank but it came back.  so i again took the tank apart and cleaned it but it came back faster this time.   i don't know how to get rid of it for good and i have no idea what it is. I'm still very much an amateur at the fish tanks but i love them.      hope you can help me and i appreciate your time.

Answer
Hello Tiffany!

I would take all your fish back to the store immediatly and start over. Either that, or get a bigger tank. 2 1/2 gallons isn't big enough for any fish, but a betta may do well in it. I would take your fish back and replace them with a singel betta.

Now, just so you know what to do for next time.

Your tank must be cycled before adding fish. Here, copy and paste this link into your browser.

http://www.firsttankguide.net/cycle.php

Next, water changes. You MUST do water changes, it is the most important thing you will ever do in your tank. Water changes must be 50% once a week or preferably 25% twice a week. Remember to use a good water conditioner like Seachem's Prime or AquaSafe.

Do not, ever under any circumstances do a full tank clean, it is the worst thing you can do for your tank. Over time, beneficial bacteria build up on your gravel, your filter and everything in your tank. These bacteria significantly filter your water, when doing a full tank clean you kill all these bacteria and the cycling process starts all over again.

The fungus will go away when you start doing water changes.

-Nick