Balancing DT light, Scrubber Time and light, needs of corals etc.

[rleahaines]

I have a 39 gal tank with Xenia corals, several other softies plus three fish.

Lots of fairly new live rock plus some old rock.

I am using an upflow scrubber with 4 X 8 screen [32 sq. inches] - one sided with 6 red and 2 blue LED's, all 3 Watts running at about 2 watts ea.. getting good growth on the screen at 16 hours on - 8 off. Feeding about 1 full cube per day of a combination of pellets, flake, dried brine shrimp, etc..

I have a new light that I assembled from a kit from Steves LED's with a combination of blue, warm white, cool white and a few UV violet LEDs. Really gives me bright Metal Halide equiv. shimmer and intensity.

The light is great, the Xenia perks up and is growing fast.

I am dosing using kalkwasser and purple up every time I add top off water.

Problem is algae on the new rocks and hair algae on the old. The scrubber keeps Nitrate down to zero and the P is below .2 at this point. [I'm using GFO and Carbon to help here]

My dilemma is this.

Do I cut back lighting in the main DT - now at 12 hours with 8 hours full sun in the middle of the day - which seems to be what the corals like? I'm getting patches of algae on the rocks . Bright green in color. I also have hair algae in several places. There is some coraline growing on the back glass and sides, but so far I don't see much if any on the rock.

I am thinking of raising the time on the scrubber to 18 hours/day - adding a reflector to the backside of it as well.

Does anyone have any suggestions to balance this better so the bad algae goes away, the good stuff stays, and I keep the corals happy?

[SantaMonica]

Should go away in a few months. Making the scrubber 2-sided will speed it up. More hours until it grows yellow rubbery.

[kerry]

I have a smaller tank with a lot of LED power over the the DT and it out powered my scrubber (Yep, algae started to grow in the display about 3 weeks after set-up). I have since changed the DT light so its not so intense and the algae has began to die off. I tried to change up hours on the DT and scrubber but to no avail because my DT lights where so powerful. If more hours on the scrubber dont work with less hours on the DT you might need to scale the DT lights back some as I did.

[MorganAtlanta]

Also cut back on feeding. What do you have in a 39 gal that needs that much food? Figure out what your scrubber will handle then only feed that much.

[Ace25]

How is your clean up crew?

[rleahaines]

Right now I have worms in the substrate and some things that come out at night, but no real cleanup crew of crabs, snails etc. I was looking at this as something I can do. Some of the packages available seem to be overkill on the quantities of animals for a tank this size.

Do you really need 30 crabs, 12 turbo snails, 12 other snails, a brittle star etc. for this size tank?

[Ace25]

It all depends where you order the clean up crew from. Most online places I have found to be a joke. Reefcleaners.org and reefs2go are 2 of the worst as far as the sizes of the specimins in the clean up crew. I have found buying from my LFS to be a much better deal even though it seems way more expensive, ie 6 snails for $15 seems like a lot, but the snails are big and will do the job of 100+ snails from one of the online places. Hermit crabs are the biggest joke, they are microscopic in size from online vendors. I have spent hundreds of dollars buying CUCs online and have always been disappointed. The last time I bought a '100G Clean Up Crew package' for my 75G and while there were hundreds of specimins in the package, it wasn't enough to even clean a 20G tank due to their size.

[MorganAtlanta]

A dozen small hermits or snails would be more than plenty. More than that would starve to death once you get things under control. Brittle/serpent stars are cool to watch, so I'd go for one of those. You might want to get an algae blenny (starry or lawnmower) also. They are a great small-tank fish in general, and have the benefit of controlling any algae that does pop up.