Clam Lighting Question

[lpsluver]

All right...Nanotuners now has a lighting retrofit kit for the Red Sea Max (34 gallons). I have the option to go with a 70 watt or a 150watt HQI. Both choices can come with or without 2 PC actinics. My tank is 17" deep (to the sand bed) and I have the tank set up as a clam tank. My question to you all is, IYO...

70 or 150 watt?
12,500 k or 20,000 k bulb?
PC supplimentation or not?

I have a chiller on the system and the retro comes with much better cooling fans than the stock fans. I am concerned with both color and health of the clams. What is the best of both worlds?

 

[seapug]

If you're making a clam tank, go with as much wattage as possible. I'd do the 150W 12.5K bulb with the PC Actinics.

 

[lpsluver]

bump

 

[hahnmeister]

Clams are very tolerant of low and high lighting. With my PAR meter I have been taking readings from many people's tanks as to what they have their 'high-light' croceas and maximas under, and even though the tanks may be considered 'high-light' with SPS up at the top, the clams often get a corner or bottom somewhere where they are only getting light levels in the 100-150 range!!! This is mushroom territory! Now, dont get me wrong, croceas can tolerate up to 1500, but that doesnt mean that they need it. Most are fine under relatively low light conditions.

As for the bulb, I would suggest 150 over 70 anyday for one major reason: options. There are only 3-7 70 watt bulbs even made that can work for a reef, and of those, only a few are available at any given time, and of those, the only one with any decent output is the Ushio 10,000K. The bluer ones have such an output drop that you cant even grow xenia under them. Seriously, two 24wattT5 bulbs with reflectors make more light, easily. And consider the cost of a 150watt vs. 70 watt bulb... you might as well go 150 (of course, that argument could also justify just getting 250watt bulbs instead). Anyways, you can get dozens and dozens of 150watt bulbs from everywhere, unlike 70wattDEs... so thats my main reason why. I would do a 150wattDE, like a 14,000K pheonix or 20,000K, and ditch the PC bulbs all together.

OR, why not go pure T5? it wont require a taller canopy/more venting... just swapping out those cruddy 55watt PC bulbs for 4 rows of 24wattT5s. Heck, you might even be able to cram in 6 rows and really scorch some corals!

But one thing is for sure, 150 over 70, and no PCs... if anything, use a couple 24wattT5s with blue/actinic bulbs.

 

[lpsluver]

Great input. Backed with data. I like that. Thanks.

 

[bklynmet]

hahnmeister made excellent points that I agree with.