Too much or Too little light

[cjtweety]

I have a 90 gallon reef tank with few fish and about 4-5 soft corals, an anemone, shrimp, gobie. I have recently change lighting duration from 7 to 10 hours thinking it would cure my irritating black slimmy algae problem. It hasnt improved so wondering what duration is best. Have a satelitte, 48" fixture puts out 260 watts of dual actinic and daylight. (4-65 watt)
Skimmer and canister filter working and cleaned regularly. HELP!

[hanas]

What kind of flow do you have in the tank? Are you running any powerheads for circulation?

[cjtweety]

No, I used to but removed it when installed the canister filter thinking that was enough flow??

[toastman]

I would increae flow inside the tank with powerhead or Tunze if you can rob a bank. Increase your lighting, 260 watts of PC lights is on the low side for coral, imo, I would double that if you can, and make sure you bulbs are newer, and use RO water for water changes, that should help

[cjtweety]

Thanks, I didnt even think about the flow, but makes sense because I started having problems soon after installed the canister and removed the power heads. I just installed new ballasts and noticed bulbs had small black ring near plug so I order new ones. Thanks so much for heads up on circulation I believe that is what may be the culprit.

[tripstank]

Black algae? Like Macro bacteria? The only thing that will help thatis scrubbing out all the phosphate, silicates, and extra nutrients. If you already don't have a refugium I would add one and a phosban reactor with both phosban and carbon in it. And of course water circulation will help too.

[outy]

if you have enough LR and the sand bed is established you dont need the canister filter.

besides flow the only thing i see wrong is id bump up sg a hair and your nitrates are high. your asking for a HA outbreak. since you didnt mention phosphate thats probably high too.

you do have a skimmer?

[tripstank]

Forget a canister filter, waste of money. How about a sump? Then you can use a reactor, refugium, skimmer, heater, and even a UV serilizer where no one will see it.

[cjtweety]

I checked phospates last night and registered between a .5 and 1.0 which according to the chart is desirable. I do use RO water so that helps. thanks for all the advice.

[cjtweety]

And yes I do have a skimmer, using a via aqua multi skimmer and does a good job. Like I mentioned the tank did very well for over a year without the canister filter so wondering now if I was suckered into buying it without needing it?? I think I'll remove it and put power heads back in and see what developes.
thanks again everyone