cyano

i would like to add that the bulbs have individual reflectors and am I just underestimating the power of these T5 HO's?

Yes, you need to move all corals to the bottom of the tank, and raise the T5s to about 7" off the water. That will help significantly. You can move corals up a few inches once a week and see if they can acclimate to tolerate the intensity and UV those bulbs give off. (UV is really more of a theory since I don't know anyone that has tested it yet)

thanks for the response melev I believe I remember reading you talking about t5's being about 7" off the water before in an article but i couldn't find the article to double check. Unfortunately that wouldn't really be very possible at the moment (a big reason i didn't get MH or LEDs was because I was unable to hang them) so i guess I need to start them at the very bottom even half in the shade? I also got my 35ppt calibration solution in today and found out my salinity in my tank was off so i have added a concentrated amount of salt to my top off water and did about a 10 gallon water change slowly this afternoon to start raising it up without shocking anything in my tank.

I had read that people who were successfully running all sps tank on T5's were getting strong penetration out of the 54 watts up to 18" down in the tank and were capable of growing sps from the tank bottom all the way to the top. I also read of people actually removing some of their bulbs due to them frying their corals. I imagine though that they took their time acclimating their sps to the higher portions of the tank. I had also read though that one very successful sps t5 reefer recommended the very colorful acro's no less than 10" to the top and the brown's and greens no less than 12-14" I believe. So how do I know if an acro is unhappy at the bottom and will there be time to save one from being fried if I just move it lower if bleaching starts to occur?

Good stuff here. I had been contemplating using LEDs for the longest time. Then I saw my friend's tank. He also has a 75 and used a 6x54W fixture to take care of his colorful array of sps coral. So, 7" above the water... seems awefully specific, definitely tagging along to find out why.

Here's the thing, you've seen what's happening in your tank with the bulbs at 3" off the water. Now try putting corals down low and see how they do. If you can create even a temporary support out of wood to get them up to 7", that should help.

A buddy of mine put me on the idea that the bulbs were possibly outputting UV, but never had the money & time to get a UV meter to measure it. It's another device sold by Apogee. Higher up should help. Or a sheet of glass between the bulbs and the water could help eliminate it, just like it does for DE (double ended) metal halide bulbs.

A couple of my fish like to jump at inopportune times (the female clown is my best example) so I am a little scared of removing my current canopy for an extended amount of time to raise the fixture. I should add that since my son goes through therapy I have nurses, visitors, and therapists in the room all through the week and my wife hates it is I leave a bucket by the tank to mix salt in I would hate the think what she would do if I took off the canopy and diy'ed a light shim into place, lol. I used to have class tops over my tank but I still experienced losses with sps So I think I will just allow them to acclimate as I have had montipora in my tank for a couple of years now and after watching it get outgrown by some of the softies I moved it to the highest point in the tank and it loves it (though it is hard to kill a monti cap) so I am assuming (hoping) it is more a acclimation thing then anything.

@Melev I had read some of your other things that had talked about having plenty of fish for sps and I know that in some your older smaller tanks you have had what would be considered to some an "overstocked" tank as far as fish are concerned. Obviously in a perfect world we introduce fish one at a time and hit a limit we have preset in our minds as to what is good but I don't put a lot of stock into the inch of fish per 3/6 gallons of water statement. So for instance right now I have one cleaner shrimp, 2 clowns, one yellow tail damsel, yellow tang, clown goby, and fire fish. Would you personally consider that maxed out for a 75 gallon reef or almost perfect?

On a slightly related tank update: the new skimmer and biopellet reactor have been running for about 2 weeks now, I have not seen any cyano blooms, cloudy water, or diatom outbreaks and I have as of last monday installed the rest of the biopellets into the reactor (500ml total) and have a great tumble. I also have increased my salt content of the tank since calibration to 1.024 from 1.020 with adding salt to the top off water and water changes (didn't realize the refractometer was off) and all inhabitants seem happier with this especially the corals. The color of the water seems clearer as of this morning than I have even seen before before it seemed there was a slight yellow ting to it and now it just seems....clean? I also have finally (after 2 years of owning it) secured the branching hammer coral to a permanent place in the reef (right next to the xenia so that outta keep that stuff in check) rather than me having to re wedge it in between rocks daily and it seems happy with the decision as well.

No, because you only have one big fish. The rest are relatively small, bioload wise. You have to look at their mass and the amount of food you have to offer to decide what your load is.

For the canopy, could you remove the lid and leave the four sides in place, using cross bars to keep it up there for a test run? Just a thought. Or you could make a taller canopy - yay! A new DIY project to start on.

@melev so for the fish that I currently have stocked what else could you see adding to that list and how many? I am just trying to get a good idea of where I stand and also an idea of fish to possibly add in the future. I have some very well behaved inhabitants right now in fact almost too well behaved as I can't seem to get them to destroy or remove my xenia, hair algae, caulerpa, or kenya tree lol. I have worried about territorial issues in stocking up to this point so I have been hesitant to add anything else that could potentially hurt any of the livestock that I have had for years.

Now that I think about it I guess i could attempt to modify the current canopy, remove the top (if I can I am at work not by my tank at the moment) add a "shim" on the inside off the canopy where the legs of the lights would rest. Since at that point removing the entire canopy or going through the top would make maintenance and feeding difficult I could see about modifying the front of the canopy so that it folds up and out of the way....I have no idea if i could do any of this with the current canopy but I can always look at it when I get home

Though if i were to make I taller canopy I would probably just hang the lights in it and have doors in the front and sides of the canopy for access......hmmm things to add to my list