400W MH vs. 192W PC for 40G Breeder

[jamesonkh]

A quick question:

I have a 40G breeder tank, and have been running a 400W MH over it. It has never been "right...." I have had a lot of algae, etc.

I am considering downgrading to 192W of PC lighting. Any thoughts on this? Would 5 watts of light per gallon be sufficient for most things? Or, should I stick with the 400W? Maybe even go with 250W MH? Thanks for any input. jamie

 

[dalbrecht]

That should be sufficient for most things.

Going with 250 might be better.

How old is your bulb? What brand?

It could be other issues. That is a LOT of light to pump into the tank. not too much but you could be depleting calcium rapidly and stunting your corals. You could also have a massive pH swing between day & night

 

[RandyO]

I run 2 96 watt PC's over my 40 breeder. I've been able to grow a montipora cap frag into a giant colony, a small stylophora into a large stylophora, and it's plenty of light for LPS like Echinophyllia, Oxypora, Euphyllia.

If you want to keep colorful Acropora, you might want to consider the 250 halide. Other than that, the PC's will work great.

 

[nwrogers]

That is a nice photo Randy. Looks like PC is the way to go for those corals...

 

[becon776]

dunno, I ran 6x 96 over a 125 and had nothing but problems and algae with the pcs.... switched to MH and problems all went away.. swithed bulbs regularly and everything.. I'll never go with pc lighting again.. I hear a lot of people raving about the t5's and many still stand by VHO but I swear... something with the pc's dunno just never had any good luck with them.
jmho

 

[jamesonkh]

Thanks for the feedback.

RandyO - That tank looks great, makes me really consider going to that wattage of PC lighting.

Dalbrecht (and anyone else) - How would the lighting affect the calcium and then PH swings @ night? Too much lighting would do that? Thanks for the help!

Finally - Anyone else have the algae problems that becon776 described, when using PC lighting?

 

[nwrogers]

I have been using PC lighting for years and never had a problem with algae. If anything you would probably see less algae because algae could be fueled by too much lighting. So to answer your question yes I use PC lights and no I have not found them to cause algae blooms.

 

[longra]

Could you post a picture of the oval coral, right middle? it looks like one that I have that I believe to be an echinophyllia. It's about the same blue-green color. Thanks,

 

[dalbrecht]

400 watts of MH halide over that tank probably exceeds the light available to your corals at their native habitat / depth.

I would look at t5's as a potential middle ground. They'll save you money in the long run. (Quick Recap: t5's have the longest bulb life of any option (18 - 24 months), and are as efficient as MH watt for watt. As a rough comparison 1 54 w t5 is slightly better than 1 96w pc & slightly less than 1 130w pc) I would recomend looking into a 4 * 39w t5 fixture.

Less lighting would result in significantly smaller differences in chemistry between day / night.

Another option might be simply shortening your photo-period with the metal halides AND adding NO flourescents for prolonged dawn & dusk to the mix so you can see the tank without the big bulb.

 

[dalbrecht]

The ph is influenced by the respiration rate of all the organisms in the tank, when they are pumping out oxygen during the day cycle they are raising the ph, when they are consuming oxygen and releasing C02 they are lowering it. Similarly, the calcium issue comes from the increased rates of calcification you are seeing from the high lighting levels. a 40 gallon tank doesn't have that much calcium disolved in the water as compared to surface areas on which coraline algae, corals & everything else is growing. If you don't have enough calcium, non coraline algaes will out compete coraline algaes. Also, coraline algae grows at deeper depths / less lighting that most of the other algaes you see in your tank. Too much / too yellow a light could be impairing its growth.

 

[Arik]

I had PC's, and the bulbs were the Current USA's Dual Daylight (6500/10000k). I had 0 nitrates, undetectable phosphates, and everything else was perfectly in line, but the algae grew like crazy on the glass of my tank. I switched to T5's and MH, and there has been a significant difference.

 

[RandyO]

<a href=showthread.php?s=&postid=7121814#post7121814 target=_blank>Originally posted</a> by longra
Could you post a picture of the oval coral, right middle? it looks like one that I have that I believe to be an echinophyllia. It's about the same blue-green color. Thanks,

I also thought it was an Echinophyllia. That was until I put it next to other Echinos, and it got stung.

I believe it's an Oxypora.

Here's another shot of it.

 

[longra]

Thanks for posting the pic. That's what I have. Need to do some research.