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View Full Version : How much is tooo much??


DiverD
11/10/2008, 07:17 AM
OK, I am debating a lighting question with a fellow reefer here in town about the use of halides and amount for her tank. She currently has very good numbers in a light fish stocked Monti/acro dominant tank. 2 Pac. Blue and a couple 3 clown gobies in 95 gallons estimated water volume including fuge. She has everything I would recommend for an SPS dominated tank equipment and care wise.

BUT, her corals don't have the "color" mine do -- and most of the pieces came from my stocks. Her growthrate is excellent, but they are slightly washed out in pigment coloration.

I have suggested she move her coral down and cut back on her lighting for this reason. She has most all of the SPS less than 3 inches from water's surface under 2 250 PFO 20000 XM bulbs that are 12 inches from the surface for 10 hours daily. My stock also uses the same fixtures but my pieces are a good 14 inches under the surface, my lighting is more than a foot from the water and I use them for only 9 hours and supplement with HO t5 420nm. My color is as good as it gets.

Is she lighting tooooooo much? She feeds and skims heavily and her 30 gallon water change is twice a month.

crvz
11/10/2008, 07:25 AM
There does seem to be an issue with the nutrient/lighting balance, and I'd definitely consider fiddling with it if she's unsatisfied with the coloration of the tank. But you didnt say anything about that. She may not care. It's a lot easier to decrease photoperiod, and I'd probably cut back her lighting to about 7-8 hours and see what happens if she wanted to experiment.

DiverD
11/10/2008, 08:34 AM
crvz her parameters were:

PO4 .02
Nitrate <10
kH 100
pH 8.15 - 8.35
Ca 480

I really didn't see a thing out of proportion and don't get me wrong, the tank looked incredible. But, her pigments were lighter and less pronounced than I would liked to have seen.

Does nobody see an issue with the absolute intensity of that much light for that long that close to the flesh of the coral? Does anybody light that intensely? Remember, there is only a small amount of water between the coral and the bulb..

DiverD
11/10/2008, 01:25 PM
^^^

ScooterBlenny
11/10/2008, 01:29 PM
What size is her display tank? Surely there is room for the corals farther down in the tank. 3" below the surface does seem a bit extreme, especially if they are exhibiting loss of color, or other signs of distress. I think your advice to move them down is right on.

crvz
11/10/2008, 03:59 PM
<a href=showthread.php?s=&postid=13716583#post13716583 target=_blank>Originally posted</a> by DiverD
I really didn't see a thing out of proportion and don't get me wrong, the tank looked incredible. But, her pigments were lighter and less pronounced than I would liked to have seen.

Not sure if we're talking past each other here, but to elaborate on what I was saying; the fact that she has measurable phosphate levels indicates that there is some nutrient excess, as once it's to a measurable level there's some concern (albeit potentially very minimal; but phosphates are very challenging to measure in aquaria and any positive only tells a very small part of the story). Drab coloration in stony corals in particular is usually a result of these excess nutrients and/or over-lighting the tank.

But I keep many corals very close to the water surface with overdriven T5 bulbs only inches a way, so I'll reiterate that I don't think it's too much light.

DiverD
11/11/2008, 06:27 AM
That .02 came hours after she did a 25% wc. I am guessing it will be higher next time we meet. She does not use any GFO, so I was impressed at a tank years old with nutrients for the most part under control -- oh, not a scrap of gha. Coraline coming out the ears of the tanks though.

I have seen some nice tanks in the area here holding SPS that had even higher PO4's, but I don't know how long that boat would float.

I still seem to think the bulbs are just so close to the flesh -- oh, and the "bleached out" effect is only on the light exposed surface.

She is going to move them down to the substrate for a while and add a GFO-TLF.

BTW, for the OP above -- her tank dimensions are 48x27x12 (custom look down style mostly set up for crocea originally)....

Thanks for the input guys.....