Looking for suggestions... T5 bulb Combos

[lorenz0]

Originally Posted by Myka

In all honesty though, I personally don't think PAR is quite as important as many people think. Water quality, stability, and flow are the most key factors to good coloring on SPS corals imo. You can have really nice SPS under modest lighting provided the water is pristine, the parameters are stable, and the flow is optimum.

Probably the best statement in this whole thread

I have seen killer tanks running only 4 bulbs but they keep up with their water quality in excellent shape

eg.

[chris88]

Par is extremely important and corals will not photosynthesis to their full capacity without enough of it, especially sps corals. Lux is just a term for brightness to the human eye while par is “photosynthetic active radiation”. It only takes into consideration the wavelength that corals use for photosynthesis, basically 400nm - 700nm. The lowest par most sps will do well with is 150 and the highest is around 600. I am not saying it can't be done other ways but this is the sweet spot from all of the data I have read which is more then I would like to admit to.
Now I am not trying to start a debate because we all know we can run a reef in many different ways and light is only one important factor. Water quality, stable parameters, etc all make a big deal. But from a lighting perspective, PAR is very important and PAR drops of a cliff the deeper a tank goes. Let’s say the par was 700 at the surface of a 24 inch tank it would probably be 100 at the sand bed with a good t5 fixture and good bulbs. Through in a mediocre t5 fixture and average bulbs and do the math it won’t add up well.

[Myka]

If I had the time I would love to prove you wrong Chris. PAR is important, but it is not extremely important. I mean, you can't grow SPS under a spiral fluorescent very well, but you don't need to blast your SPS with as much PAR as many people like to, or think they need to.

[chris88]

Myka i do partially agree with you. Some people are too concerned with par but I was just stating what I have read from research articles and test done with Par and coral growth. It is a fact that most sps or corals in fact will grow faster with more light aka higher par numbers. But there is a limit to this, after a certain point they become saturated and photo inhibition will occur and it can be harmful to the coral. 600 par is not that high, and 100 is actually very low. Put a sps frag on your sand bed vs. 4 inch from the surface and see which one looks better and grows faster.

[Myka]

Chris, I have only two SPS corals that would handle being 4" from the surface under my lights (a tabling Acro and a Candlelight Acro). They are halides, but the fixture is Chinese and the bulbs are from Home Depot (came with fixture). It is a 36" fixture over a 48" tank too. It has two T5s (UVL Super Actinic and KZ fiji Purple right now). Needless to say, this setup isn't high output by any means. I have Stags and Milles on the sand in my 24" deep tank that have better color there than higher up. All my LPS corals are off to the side away from the halides. My water is crystal clear though, so that makes a huge difference.