MH lighting question

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Brenden

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With a total water depth of 31" (top of sand to water surface) Is 250w MH sufficient or do I need 400w lights? Tank will be housing all varieties of coral and the ones that need more light can be placed on lr that is up to 20" tall.
 
http://www.reeflightinginfo.arvixe.com/

Sanjay's research actually shows that there are some 250w bulb/ballast combinations that out perform many of the 400w bulb/ballast combinations with par at 18".

If I recall correctly (and that's questionable) Sanjay says that a par value of 100 or more is necessary for the corals to thrive (I just can't remember if that is where ever you are locating the coral or if we're talking at 18" hopefully it is burried in his website somewhere). If you got a light meter you could determine what your par is at the bottom of your tank given your current bulb/ballast setup. I would think that you could easily keep happy shrooms, sun corals, zoos, etc with the lighting you currently have at the bottom of the tank. My 250s are bleaching one of my shroom colonies at the bottom of the tank and that's at 24".
 
HQI or Mogul Bulbs? I believe the 250w is just fine i just would keep sps corals out of the substrate (which you should anyways) and you're fine. Maybe consider placement of clams as well though i think they should be fine.
 
Oh yeah perhaps considering replacing the bulbs slightly more frequently than manufacturer recommendations (which depends on the bulb) when spectrum starts changing the corals lower down will tell quickly.
 
The 250w I have now are Mogul retros. I am buying additional lights and was looking to purchase HQI pendants. I could add more 250 pendants and remove the retros and replace them with pendants using the same ballast. Or I could add 400w pendants between the 250w MH I currently have or I could replace all the 250w with 400W pendants. I am just trying to decide if I need 400W lights or not.
 
Thats up to you... depends on where you wanna go with the reef and the type of corals you mainly want to do. If you want to have a major SPS reef maybe upgrade... if you are going to have a euphylia LPS reef then why spend the money? spend it where it would be more useful to the tank... your tank would end up looking better to be honest. But i mean it all depends on where you wnt to go with the tank. Remember there is no one way to do a tank there really are no specific rights or specific wrongs (though there are a few of those).
 
250W lights should be fine. IMO 400W lights are just too much for most any tank unless you have over 36" of depth. The heat 400W lights generate is quite a lot.... :(
 
yes i mean that. But i mean this only if LPS is the type of coral you want to do. Im saying find what you like and focus on that. If you are doing LPS then it would make more sense for you to save the money on lights and say pick up an effective wave maker or two. These are just ideas. I am of the firm beliefe that you build the tank around the corals and not the other way around
 
Well, IMO, with a 525 gallon reef you obviously have a respectable budget. I would pick up an Apogee PAR meter (Model QMSW-SS about $300) and actually test what your lights are doing for you now and go from there. The unit has a sensor that can be submerged.

Pricey, somewhat, but if you think about it you can get detailed information how to choose the best wattage for your tank and also the best time to change bulbs, etc. I think it is a value that could pay for itself with a reef the size of yours or at least give you peace of mind.

My own opinion, I think 250w would do you fine with your SPS in the upper 3/4 of the tank (regarding what lighting they prefer, not all SPS are the same) and the lights spread out with the proper 2'x2' coverage area.
 
and it could become quite lucrative too, you can "rent" it out to folks ;)

I know if I had access to one, I would be interested in the readings.
 
Dana Riddle tested it, and apparently was pleased with the results. It is a pretty good alternative to the only other ones available, the LiCor models are over a $grand$. The Apogee is a scientific sensor in a hobbyist housing :wink: . I would loan it to other hobbyists by "hand transfer" only over shipping....although a weekend rental with shipping for $150 should cover things nicely. :mrgreen:

I'd head right to your local reef club........
 
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