I've been noticing a mildew or even light mold in a circular area on my tank hood and side of the filter. I wipe it off, but it comes back in a couple days. Is this normal? Should I wipe with a bleach mixture? (If so, how much?)

Also, how often should I change the tube and suction cups on my airstone? They seem to be getting cruddy...

Gracias!

There is a big difference between mildew, mold and algae that may be on your hood and such. If it is very wet, chances are it is algae - algae can be black, slimey yellow, green and many other colors. Simply wipe that away at each water change.

If you really have mold or mildew on the pieces, take them apart and wash them and clean them in a bleach solution of 1part bleach to 10 parts water. Make sure the surfaces stay wet for 10 minute with the solution. That will kill it.

As far as the hoses - most likely the air hoses just have algae on the outsides. Simply wipe them off. The suction cups, too, can be wiped. My suction cups usually die after about 6 months - and I replace them when they cease to stick.

I've also noticed a white substance on my hood lately, but I think it is actually salt! My airstone throws up a lot of water onto the hood, and as it evaporates, a white residue is left behind. I have the tank at .3% salt for a new fish, and have only noticed the white stuff since we added the salt.

I suppose I could taste test it to be sure...or maybe not.

At your next water change, you can wipe the area with a papertowel with a bit of lemon juice on it (don't make it super-drippy). It'll help clean the algae/whatever off and hopefully keep it from growing back so quickly.

so i cleaned the lid and side of the filter with a mild bleach solution...seemed to get it all. hopefully it won't grow back too quickly. it might be salt, but i'm thinking it's more mildew-y given the pattern it's 'growing' in.