MH upgrade to PC lighting

[fishy929]

Hello all! I'm new to the forum and I'm thinking about upgrading the lighting on my 55 Gallon reef tank. I have some Ricordia's and a leather right now, but I decided that I didn't want to be limited to the types of coral I can have. Here's what I have:

48" JBJ Formosa DX 4*65 PC lighting w/stand (raises it about 2-3 inches from the top of the tank)
2* 10,000K daylight
2* 6.500K Actinics

So, I just ran out and bought this lighting last month (before I knew what I needed) thinking I would be happy with a FOWLR tank...NOT! Does anyone have any experiences to share regarding altering a setup like mine? I was thinking of dual 175W or 250W MH lights. I say dual because I guess I need to work around the crossbar in the center of my tank. Kinda like this configuration in the center of the hood (use your imagination) <==|==>

Any comments or suggestions on the right thing to do and the best place for parts?

Thanks!

 

[liquid]

I would say go with the 250 watt halides and go with a dual setup. Personally I like my PFO retro kit I bought from Premium Aquatics. I went with a dual 250 watt PFO ballast, morgul socket, and two 6500 K 250 watt Iwasaki bulbs. Some people claim that they look too yellow but to be honest the coloration is pretty similar to what you'd see out on a reef flat. Some people like the 10,000 K's because they're more of a 'white' look to them. Also, some people also like either the 150 watt or 250 watt HQI halides as well. Some things to note:

* as you increase the color temperature of your bulb (°K), the lifespan of your bulb decreases. I can get about 12-18 months out of my 6500 K's whereas 10,000 K's may get around 10-12 months or so.

* the best PAR bulbs seem to be the 6500 K Iwasaki's or the 10,000 K halides on a HQI ballast.

FWIW, I personally believe you can keep just about any coral (within certain guidelines) with 250 watt halides. I'm primarily a soft coral guy and I've never had problems yet w/ this setup.

If you'd like to see my tank, head over to http://www.liquidreef.com/

Shane

 

[liquid]

BTW...here's a good page on halide lighting: Click Here

And here's the halide retro kit I bought: Click Here

The Sunlight Supply and the AquaStar/Space hoods are also very good too.

Shane

 

[fishy929]

Liquid,

How much more heat is generated from a 250W vice the 175W bulbs? Since my hood is about 3-4 inches off the top of the tank, I'm concerned about too much heat. As it is, I rarely dip below 80F and top off at around 82F. My hood has two 2" fans.

At 2*175 watt MH and 2*65 watt PC Actinics that puts me at 8.7 Watts per Gallon on my tank. Wouldn't that be sufficient?

 

[Anonymous]

I have 2 X 175W 10K and 2 x 110W VHO actinics. I like the look. My tank tops out around 83 each day. I really wish I had 250's. That way the acros on the bottom would grow like the ones on the bottom. I'm sure adding another fan would cure any heat problems.

I like keeping my bulbs 8" above the water. You will have to build your own hood to do that though.

Louey

 

[liquid]

As you increase the wattage on your bulbs you will naturally put out more heat, so a 250 will put out more heat than a 175. How much is anyone's guess. I've never measured it. I'm pretty sure you'll need some larger fans as a 2" fan doesn't move much air -- maybe 30 cfm tops?

If you'd stick to soft corals and no clams I'd say you'd be fine w/ the 175's. If you want clams you'll probably want to go w/ 250's instead. I'm sure others will have differing opinions tho.

Shane

 

[sstephen]

I don't mean to butt in to the conversation, but does he really even need to replace the lighting? This is for a 55 gallon tank, after all, which is probably pretty shallow (probably 20" or less, right?). Correct me if I'm wrong, but metal halide lighting is supposed to be superior for deep tanks which require more light penetration. It also depends on the light needs for the coral species that are actually in the tank. You should be able to accomodate corals with medium to low light requirements (maybe even some shallow water species placed near the top, they can be pretty good at adapting to lower light) with the current setup. I understand that MH setups put out way more light than PCs, but there may not be any need to replace expensive lighting with an even more expensive setup. It may not even be practical since the MH lighting needs to sit higher off the water than your current setup (like 6" - 12"). Check out the Metal Halide FAQ on WetWebMedia. I saw at least one FAQ dealing with this size aquarium in which Steven Pro recommended your current setup over the suggested one.

 

[liquid]

One of the requirements was to recommend a lighting scheme that would allow the poster to not "be limited to the types of coral I can have," thus my recommendation to go w/ halides. PC's definitely have their place, but as I understand correctly, PC's really should be replaced every 6-9 months due to spectral shift and decay of light output. I can get about 18 months out of my Iwasaki's, so every 18 months I pony up $60 for a bulb and I'm set. My gut feel is that you'd have to spend more than this every 18 months for PC's but I could be wrong. Also, personally I would not attempt clams or SPS under PC's with said tank, but I'm sure that there's someone out there that's had success with it.

FWIW, my halides are 4" off the water for the last 3 years w/ no problems to date.

YMMV

Shane

 

[sstephen]

I totally agree with what liquid said about raising tridacnid clams. Although derasa and sqamosa clams do well with less light, the Tridacnid Maxima might be better suited for a 55 gallon (they don't get as big). Most shallow water photosynthetic organisms such as clams, SPS corals, and anemones will have similar requirements for high light output. But that doesn't mean that PCs can't be used for these. The only way to really tell how much light is required and how much light is supplied is with a PAR (Photosynthetically Active Radiation) light meter. However, since most of us don't have these, we have to do research into general requirements for the species, combined with knowledge of the kind of lighting the organism was grown under or the part of the reef it's from. PCs in shallow tanks can be just as effective as metal halides in deeper tanks. But your comment about replacing the lights is definitely valid. I've heard that MH lights do last longer than fluorescents and that may save some money on bulb costs.

The following quote came from WetWebMedia.com (again I highly recommend checking the FAQs on this board before making a purchase) made by Anthony Calfo:

"Case in point... if your tank is 24" or deeper, MH lamps may be necessary just to keep moderate light animals and more so for sps corals and clams. In this regard MH are 'better' as they penetrate whatever deeper with better PAR. In terms of useful PAR per wattage of power consumption ('efficiency' or 'bang for the buck') ... MH also performs much better than PC or VHO. However, if you have a shallow tank (under 18") and want to keep soft corals and mushrooms... MH will be harmful and PC would be very fine! It all depends on matching your selected inverts needs at depths to the abilities of the lamps to penetrate with useful light"

Other things such as general water quality, water movement, and even aggressiveness of the different species will prevent fishy929 from having a tank that can support any and all corals.

Sorry, to ramble on, but I just thought that it might be possible for fishy929 to save some money and still have a very diverse reef tank.

- Scott