I have a 20 gallon tank with 3 small clown loaches that I've had for about 2-3 years now. The overall tank has been in operation for about 5 years, maybe a bit more. I have a hob
top fin 40 power filter and an undergravel filter with a small power head. ( I have had the undergravel since starting this tank) I also have an air stone at the opposite end of powerhead.
For about over a year now ive been having issues with brown algae
that accumulates on the walls, gravel, but mostly on the decor... I try to do water changes every 2 weeks but sometimes it goes a bit longer. I also clean gravel when i do the changes. I usually only take out about 4-5 gallons when doing the change. The brown algae ussually comes back very quickly, sometimes after only 2-3 weeks. The tank looks very clean and clear except until the brown algea gets bad...
Yesterday i did a water change and cleaned all the algae. I really got the vac down against the undergravel filter plates all over and pulled out a LOT of crap, making the water pulled out in the bucket BLACK... I even did a double water change so to take time with the undergravel filter crap.. ( i usually do not go that far down to the plates)
I started to think that maybe my brown algae problem is being caused by the undergravel filter being so dirty. So i decided to test this out and disconnected the undergravel filter to see if the algae returns as fast, and just run the hob
filter for a few weeks to a month.
I am starting to think that maybe that is not a good idea to let all the crap that i didn't get out just sit under there without the undergravel filter running? If anyone can chime in on this id appreciate it! Thanks!