Another Question: Trouble with Light and Flow Balance

Had my 90g reef up and running for 6 months now. Water paramaters are all normal. I have 2 clowns, a firefish, blue tang and a scooter blenny so far. All the fish are healthy and eat well and have been in the tank for months but refuse to venture to far out form the righ back corner of the tank with the exception of the blenny which roams all over. All the snails, crabs and shrimp fly all over the tank like they own the place. When I shut the lights, main pump and MP40's off all the fish roam all over the tank like I would have expected them to do normally. I initially thought that they were just getting acclimated to the environment and would eventually pick territories and roam a bit but the clowns have been there for about 3 months and the other fish about a month and still just hang in the corner. I decided to reduce my MP40 flow down to 50% thinking they were gettting blasted but no dice + I think that is now contributing to an algae outbreak (see my prior post on algae in the fuge).


I have a Vertex 3' Illumina SR260 that I was keeping on for 8 hours at full power about 4" abovet the tank. Thinking the light was too intense for them I reduced my light output by 10% and raised the lights off the tank by about 3 - 4 inches and still no dice. They still hug the back right side.


I have a light meter so I am going to map the tank again at lower light levels to see what I can get away with in reduced light to see if that helps but I dont want to starve my corals either. I suspect that my lights are probably too bright. I have an SPS that dumped all its color about a month after I put it in. I lowered it in the tank and it seems to be doing a little better so I think I can get away with giving the fish a break.


Any thoughts here ??

 

I am pretty new (6 months) I am well researched but lacking in experience obviously. First reef tank. The tank seems to be doing pretty well otherwise. I have had no real issues up until now. Water parameters have always been right on thus far.

The fish are fairly small. The clowns are about 1.5" but growing pretty fast. They are a lot bigger then when I bought them. The fire fish is about 3". Blenny is about 2". For coral I have 4 SPS frags, two are doing really well the other two were higher up, more sensitive and suffering from my light mismanagement I think. The rest are zoo's, bubble coral, frogspawn and torch coral along with a clam. All of those are doing pretty well but they are lower in the tank too.

I have a 900gph Iwaki return that calculates to about 4-5 times turnover via the calculator on RC. However there is quite a bit of laminar flow coming from the return that seems pretty powerful. The Iwaki also feeds my fuge. About 25% of that is directed towards the fuge the best I can tell. I have been thinking about toning down the flow from the sump but that makes me nervous. Don't want to fall below 4x really. I already dropped the MP40's I have to 50% plus for 10 hours on night mode they run at only 25%. The fish seem to love it when I turn the Iwaki off so it seems like the return is kicking the crap out of them.