How to get rid of slime in my tank?

I have been a fish aquarium hobbyist for 15 yrs and I have never encountered this problem before. I have set up and maintained several tanks of different sizes with many different fish species and if anybody knows what they are doing it ought to be me! So, I do not understand what is happening here and it is costing me much $ to fix! This slime developed on a new tank in a matter of hours and it is covering everything and clogging up the filters. In less than 24 hours I have had to change out the filters like 4 times! I kid you not! I finally removed everything and cleaned everything,but, in just two hours, the slime was back again-everywhere! And the filters were getting completely clogged up once again. I have a top-of-the-line filter,too. The slime looks like snot. My fish have tried to eat it thinking it was food, only to spit it out, of course, when they realized it wasn't. I keep checking the water conditions-nitrites are a little high of course due to the tank being new. I have having some trouble with the Ph-a little high, but, not bad. Ammonia levels are staying at around .5 despite water changes, filtration and use of Stress Coat. My fish are very stressed, I can tell, from the ammonia and all the water changes. I am changing out 25-50 % of the water every other day. Been doing this for just over a week. I even added a little salt. Nothing is helping. I do not know what kind of slime this is or if it is dangerous to my fish. Help! Things are getting out of control! This problem is taking over my life! Also, I cannot tell if there is a smell because I have very poor sense of smell and I have no one to ask to smell the tank for me (no one who will do it at least). I do not know what to do. I have tried everything. Even the fish store guys (yes, plural) doesn't know what to tell me to do.