The brown gunky looking algae that takes over anything in the tank it can rest on such as decorations, plants (live and fake), etc. It is supposedly Diatoms. I have a 30 or so gallon tank with ion exchange softener water in it. I started with an albino cory and a giant danio and some hermianthius cuba. also the usual, gravel, decorations, fake plants. and a single 24" old old old fluorescent. Plus a ton of snails from a friends tank. i like snails. 5 kg of black medium Fluorite.
In no time at all I had brown stuff growing on everything. the "cuba" died off after a few weeks. eventually got some more fish and a pea puffer and some plants. supposedly water sprite and saggitaria. ive spent hours lookin up the plants i now own and i think the water sprite is actually western milfoil and the other one i cant rememeber what it is. started with 5 stems of the milfoil and a mother and daughter plant of the other one. the milfoil grew a tiny bit over a few months and the only part that was ever green was the very top, the growing part. the rest was pale and brown/yellow and sickly looking.
I went from 5 milfoil stems to two half stems and three 1 inch pieces of broken off plant that got stuck in my fake plant. added 1 co2 reactor and it simply slowed down the death of the plants. so after a few months of the glass getting covered in green algae that needs many passes with a firm razor blade and the plants covered in brown. i went to canadian tire, bought a ballast, 2 different fluorescents and some other crap, i chopped the light hood apart and extended it to fit the two 3 foot fluorescents. 1 is a general 4100K 25W and the other is a fish store 4200K 30W i think. the original was a 12 or 15W. I also found a
deal on another CO2 reactor and bubbler ladder. added that and am using a sugar and yeast solution instead of the packets. Now the good part.
Didnt notice much at first but then slowly and then faster. the little 1 inch pieces started growing roots through the fake plant and into the gravel. the 2 half stems started showin green at the tops and growing. then like someone flipped a switch my 2 shot up to the top, i cut them in half and replanted the half pieces, those four started growing. Then the brown turned to yellow which then was only left on 1/10 of the plant. the rest was a much more vibrant green. so the other day i ripped the 1 inch pieces which are now about 7" out of the gravel and fake plant, they ahd about 7" of root in the gravel as well. replanted those and cut some of the others in half again. all seem to be doing very well.
Did a final glass scraping with the razor. no more green algae dots reappearing but the existing ones which ar eon some of the plastic filter pieces arent going away either, wont come off with fingernails or tooth brush, VERY tough algae. but at least its not growing any bigger.
One word of advice, FOr plant growers. Forget the CO2 reactor if you have ANY snails!! i mean ANY snails. or if you dont want to fiddle with new solution every few weeks. Just dig deep and get a CO2 bottle and regulator and solenoid. So much stress/hassle removed. I've given up being careful with the snails that crawled onto the bubbler ladder. i hack at them if i can reach them with the tank fork until they let go and fall away, only to climb back onto it and block the bubbles about 15 minutes later. I've even had them crawl intot he air line thats suppplying the CO2. freakin snails. but they do keep Pea puffers SUPER DUPER happy. and super fat as well.
i have since added another hermianthius "cuba" to my tank in hopes that it will take root andspread around a bit.
And a few more fish. 1 pearl danio, 2 zebra danios, 2 penguin tetras, 2 pea puffers, 1 oto, 1 albino cory, 1 electric yellow cichlid, some ramshorn and some pointy tubelike snails
Thanks for the tips, they're always welcome.