Macro Algae (chaeto) not looking so good.


New member
For some reason my Macro Algae (chato) isnt looking very healthy.

Its becomming brittle and the brittle strings are white and are falling lose with very little effort.

I don't think I changed anything so many something else has changed?

I use one bulb that Melevs suggest on his site, and another one from home depot, had good growth for 1yr.. could the bulbs being going bad? they are about a yr old.

One last question, do people get best results when they just leave the light on 24/7 in their sump? been doing that for method since i started.


Premium Member
no. not 24/7 it doesn't give the algae down time. You'd do better having it on a reverse cycle with your tank and add a bit of iron supplement. Mine was on 24/7 for a while and started to dwindle away. Then I figured out the deal (actually somebody here helped me out, I think).
Try a cycle. See if that works.


Staff member
RC Mod
I run my small HO light on it for 20h, 4 hr off. The cheato is dark green and very vigorous.

Do however be suspicious of any bulb over a year old. Some bulbs are done after 6 mos. In this hobby, don't wait for bulb to burn out: they change output much before that event, and will have things going bad for some time before they ever burn out.


Carpe Noctem!!!
Premium Member
I would cut back the brittle dead parts and do about a 12 hour light cycle, opposite of the tank's lighting as mentioned above. Personally I would see how this does before adding iron supplementation.