How far off the sandbed are your lights? If they are t5's you should probably just rest them on the rim of the tank - from what i read (could be wrong) t5's max out at a depth of 20-24".

The Powermodules have much higher PAR than all other t5ho fixtures so they still work well at those depths.

Reefgeek has 10% of this weekend on the sunpower models.

My tank is only 18" deep and 2 of 3 clams are about mid-tank.

Every tank and LFS I have seen the clams are wide open and impressive with high light levels. When my lights are ramping up and shutting down my clams don't open more so I don't think this is the case.

Levi, Lorenzo, John and Doug:

Hey fellow's what brand of fixture's and bulbs are you all using. I would search all your tank builds but I don't have much down time ATM, big job on the go working 7 days a week up to 18 hrs a day. Thanks in advance guys for your time.

I am using the same as Wes, 8x80wt ATI PM :mrgreen:

A great investment IMO

Fencer ok are you saying that just 2 400's are enough for his tank. the reason im asking is my new tank is 96x24x24 and its going to have about 2-3 " bed and what i have now os 2x400w 20k xm's i thought about going to a higher kelvin like xm's 10-15k or should 3 be enough on a 8 footer ....

I agree with Doug, why not use bulbs that give more par value, Figi's and blue bulbs enough blue/purples in coral, but IMO do not give the light par value that would enhance growth, and what clams would use.

Before spending money on changing the fixtures, I would suggest just trying a different bulb combo, replacing maybe one or two bulbs only for now. See how that goes.

I am a fan of the MH, but I must say many of you have gorgeous setups and happy coral with only T5HO, so getting the right config and right number of bulbs is the key here. I wouldn't just change to MH, just yet, if you don't need to.

I agree with Doug and Sphelps. I think you have enough light now on an 18" tank. Before you go and buy a new fixture try some other bulbs. More bulbs in the 10000K range and you should have plenty of the right light.

Ok I have some spare bulbs that have not been used much that are 10,000k and 12,000k so I will give them a go.

Holly crap I almost died when I read this and the other post. I really think people need to do some research before they start blasting off facts. Look at the par values for the T5 bubs that are out there. The highest par bulbs on the market are KZ, ATI, AQUA SCIENCE, and some UVL. There isn’t any bulbs on the market then the Kz or ati bulbs.

KZ NEW GEN 315
KZ CORAL LIGHT 340
KZ FIJI PURPLE 330
KZ SUPER BLUE 310
ATI BLUE PLUS 320
ATI AQUA BLUE 330

Also have most of you even looked at a chart showing the spectral intensity the corals photosynthesize at? Well I will have to show you then. Corals only use blue and red spectrum for photosynthesis. The problem isn't your bulbs it’s your fixture. You should have better reflectors and more bulbs across the tank. I suggest a 6 bulb or 8 bulb tek or a 6 bulb ati fixture. 4 t5’s will not truly cut it for sps and clams unless they are mid way up or higher.


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