Can you have too much wattage?

[college429]

Question #1: I'm stumped? What could be going on here?
I currently run two 175 watt MHs on my 55 gallon reef. I keep acros, pocilloporas and zoos primarily. Would they benefit from an upgrade to 400 watt? Would I see faster growth? Could this upgrade cause any problems, like be too much for my small tank?

Question#2: Ok, I give up. I need to consult with the experts. I can't keep my Calcium or Alkalinity up. Calcium is always below 400 and alkalinity is always also just barely at the lowest of the acceptable range. And this after I add the maximum daily recommended dose of B-ionic. I've tried to supplement with another calcium and alkalinity additive and it doesn't help. I've checked the magnesium level and it is fine.

Finally...

Question #3: I've noticed some of my sps become pale after adding them to my tank. I don't think it is the color of the bulbs, it is a gradual paling. This is quite apparent in the brownish ones, but also noticable in my orange cap. Could this be because of less UV? Would an increase to the 400 watt mhs help?

Thanks for taking the time to respond. I could really use some expert advice.

[Imaexpat2]

I think and its just my opinion that 400 watters would be a bit excesive on a 55 unless you are using 20K bulbs. 250's would be more than adequate, even with 20K bulbs. I dont think you will see enough difference in coral growth or color going to such a set up as 400's. Your electric bill will definitely take a hit though!

175'S should do you well until you get to 24 inch tank depths, 400 for anything much over that, ie...30 inch or deeper. 250's will do fine in most cases for anything in the middle, is the general rule I follow on my tanks and frag systems

[M.Maddox]

What's the kelvin temperature and the PAR range on your bulbs? How old are they? What lux is actually penetrating to your corals?

[college429]

I don't know the Lux or PAR of my current bulbs. They are both about 10 months old. One is 6500K the other is Sunburst 12K.

[ACIDRAIN]

IMO, the bulbs are probably needing replaced about now.

As for your questions, IMO;
#1and #3; The bulbs are needing replaced. As the light intensity fades over time, the corals will fade also. Myself, and many others I know, replace MHs about every 6 months. I use my "used" bulbs then on my FW plant tank for another 6 months-year.

#2; What kind of substrate do you have? Is it calcium based, such as aragonite, southdown sand, crushed coral, ect? Or is it innert, or bare bottom tank? If the substrate is calcium based, then this will help keep the hardness up in your tank, and thus keep the calcium from dropping. If you have a bare bottome tank, then it is the same as having an innert substrate. Are you using RO water, or tap water? Tap water is usually hard enough to keep both of these up, but RO water is not, so you need to add something to it to increase the hardness of the water. There are several products out there that are great as doing this. They are designed specifically to add to RO water, the needed "extras" to harden the water, as well as keep the nessecary trace elements in the water.

HTH.....

[college429]

Thanks,
I'm using RO/DI water. I've got Aragonite on the bottom.