Are My 400 watt MH Too Strong For My Tank?

[mcfly]

Ok kinda going nuts here. I have a 6' long 125 gallon reef tank i start last October, I have been taking it real slow due to having no money. Well so when i finally purchased my lights in December i went back and forth between retro fitting two 250 watt mh or two 400s. So decided to go with the 400s, I bought a GE balast and capacitor and mounted everything in a metal box and then bought a reflector and cheap 14k bulbs from the ebay. My problem is i cant get any coraline growing on any rock exposed to the light. all my rocks undearnth are caked with coraline but within days of turning them over they start to fade out. After about 7 months of this i decided to purchase some decent bulbs so bought the SPS 14k bulbs have had those since july. But i am still having the same problems.

What is going on here or anyone else have this problem?


I do have coraline growing on my glass and overflow btw which is what i dont get.

parmaters today

ph-8.2
calc-440
salinty- 1.25
mag - 1300
dkh-7
temp-80

 

[Hookup]

I have the same thing under my 400w. Corals all grow fine, the ones that are high-light loving that is... but the very upper rocks, say 12" or less from the direct light (surface), do stay white.

So, yes, it seems normal to me, and no, I wouldn't worry about it... I don't anyhow... been a year+

 

[framerguy]

Can you raise the lights a little? I think it would be a good idea. 400 is a little excessive for that size tank. Unless you have a 36 inch deep tank and need the penetration then 250 would have been more than enough. But...now that you have them, try raising them about 12" and see how it goes. The next step would be to trade them with someone for 250's.

 

[cbrownfish]

IMO the big consideration with 400's in a warmer climate (VA/NC versus Ottawa) and on a modest water volume, is the potential heat issue. 400's add a significant amount of heat and you will need a chiller if your entire system is not in a top notch climate controlled environment (consistent temp and good ventilation).

 

[mcfly]

Thanks for the input. It is a standard 125 gallon tank (72x18x22)The lights can not raised as they are mounted in the canopy. But I made it through the summer fine. I believe I saw the temp hit 84 once or twice and in the winter we keep our house so cold i had to run 2 heaters.

I wanted to go with three 250 watt metal halides when i first was setting up the tank but my center brace would shadow the middle fixture so just went with 2 400's but this seems to be too much now.

I suppose ill keep my eye out for two cheap 250 watt ballast and capacitor i could swap out.

 

[BigAl07]

mcfly I think you would be better suited with 250w fixtures but if you're not having problems with 400w then I wouldn't change and I wouldn't opt to less than really GOOD ballast and equipment.

 

[mcfly]

Ya, i think i have decided to buy 2 new ballasts and 2 new sps bulbs. wish i didnt have to spend the money but think it will all around help my tank bc some softies actually seem to close up a lil when the 400s come on.

prob about 80 bucks for 2 new ballast
and about 120 for 2 new bulbs.

Ha wanted to make sure i had the best of everything for my tank but guess i went too big with these.

I Attached a picture of my current ballast set up, I just bought 2 GE ballasts and a 15 dollar tool box from home depot and mounted them to the sides. Saved a ton of money!

 

[Frankie]

400w is fine over that tank. I had two over a 120 with awesome results. Radium's work perfect at that wattage. Like mentioned earlier it is temp that you need to be wary of. A good fan system will make a dramatic difference in heat transfer and cost less then a chiller runing all the time.

 

[mcfly]

ya my tank temp is fine. Frankie how deep was your tank and how high were they mounted off the water because my tank is 22 inches deep and my bulbs from the center of the bulb to water level is 6.5 inches. I have a really short canopy. which i assume why my rocks are bleached out on the tops.

 

[Frankie]

Mine were about 6-8" off the surface. The tank was 25d

 

[mcfly]

thanks for the input. tank looks awesome and looks cool have a clam as your center peice of the tank