What is this?

[nazgul1979]

1 1/2 year old 72 gallon bow with 55 gallon sump/fuge. 0 ammonia, 0 nitrite, 0 nitrate, 0 phosphate. Run a dual reactor with GFO and carbon. Also have HOB filter on fuge (was just laying around so figured why not). ATO with kalk. Chaeto and prolifera in fuge. All of the sudden I've had this brown algae covering my rockwork. Any ideas what it is or what could be causing it?

 

[aguila88psi]

Check your RO system, chances are your topping off with water that has silicates or phosphates.

 

[nazgul1979]

I can check RO for phosphates (0 in the actual aquarium but I run GFO so maybe they're being removed) but how do I test for silicates?

 

[aguila88psi]

What is the tds of the output of ro system? If its higher then 1 then it probably has silicates or phosphates.

 

[nazgul1979]

Have an inline TDS meter and it's 0.

 

[Hexacorallia]

how old are your light bulbs? Also the duration?

 

[nazgul1979]

Light bulbs replaced in February - all ATI, 1 purple plus, 2 blue plus, 1 coral plus. The 2 blue lights are on for 11 hours, the purple and coral for 7 (in the middle of the blues being on, of course). LED moonlights on for an hour before and an hour after other lights. Fuge light on alternating hours.

 

[Hexacorallia]

seems like its just diatoms. got any astrea snails or other snails? they will munch it pretty quick. i personally run my lighting on 8 hour total duration and change t-5s about every 9 months. also any ambient lighting from windows will help diatoms.

 

[nazgul1979]

there is a bit of light coming from a window (especially now that it's summertime). That certainly might be contributing. I feel like the light is too long but hate to not see it at night (only time I get to see it). Probably the problem though along with the light from the window.

 

[sirrealism]

Change your timers to come on later so they can stay on later. My lights dont come on till noon then go off at around 10pm

 

[Hexacorallia]

^^ exactly. I personally do a total 8 hr duration. take the time i usually go to bed and count back 8hrs, that's the time the tank turns on and that way im home enjoying it wile its on and not on when im gone. Also during the evening hours its usually cooler, less peak draw for electricity. In all my production systems i run at night time.

 

[snake1]

have you calibrated the TDS lately mine was way off showing 0 when it was actually around 3-4 I would start there.

 

[nazgul1979]

I have not calibrated for a long time so that could certainly be it. Have a handheld TDS meter I'll check it with when I get home and let ya'll know what it says. Thank you all for the help and great advice on this, btw!