lights on / off ?!?!?!

[mike b]

ok....125 gl. with about 175/180 lbs. live rock.
60 lbs. from a mops board member ..beautiful green
and purple coraline coverage. the other 115 from
big als..most cured, some not.
just now going through some nasty brown algae..
pretty much covering everything that's hit by the lights.
lights...hamilton tech....3 x 175MH + 2 x 40W NO actinic.
at first had light running 8hrs MH's and 10-12 hrs. NO actinic.
now down to 2-3 hrs. MW and 8 hrs. actinic.
what do you fellow members think...what did you do ??
how long did you experience first algae outbreak??
i read anywhere between 1 and 3 weeks .
so far for me...1 week.

thanx.

[ajx22]

First off...what (if any) livestock do you have in the tank? If you don't have any light sensitive livestock (corals) then lights off won't be a problem.

What you are experiencing is called Diatoms. It's a normal problem in new tank set-ups, but still a PAIN :mad: . What you read is correct...give it a few weeks and it should start to receed. Things that will help in the 'fight' are:

use a good skimmer
high water circulation
HIGH QUALITY water (RO/DI) - no phosphates or silicates
trace element additions (calcium, carbonate, iodine - to help the Coralline grow)
be sure your're not over-feeding


If all your levels (Nitrite/Nitrate/Ammonia/Ph) all all stable at their proper level - you could add a few Red Scarlet Hermit Crabs to help too. Be sure to dose with Iodine is you have hermits though.

Another way that will help your system in whole; is the addition of a refugium with macroalgae (caulerpa, etc.). Excess nutrients in the water will allow for algae blooms, but the macroalgae will assist in lowering these levels, and thus reducing microalgaes.

I have a 3-month old 100Gal FOWLR, with 35Gal sump, x2 175watt 5500K MH's and 8 PC actinic's. Only livestock is 2-Domino and 2-Yellowtail Damsels + 5-Red Scarlet Hermits + a few snails --- only using RO/DI water, and am dosing Seachem (calcium, carbonate & iodine) --- still a SMALL amount of diatoms present, but disappearing quickly.

Hope this helps,