i found some yellow algae attached 2 my aquarium wall. i just wanna know is it good 2 have yellow algae instead if green algae? i m using a 4ft tank with two ryukin and 2 bio foam air driven filter.

i m also trying 2 find out how long can my water stay in good condition by using two bio foam filter as filtration. anyone here knows how 2 detect bad water? the only way i know is 2 smell it.

The last time i change my water was last friday and yesterday i made some testing on my water and found out the nitrate level is 0.1(pretty low), ammonia 0.0, pH 6.8(quite high), i fed my ryukins 4 times a day. any comments are welcome.