some sps remain brown

[Kinerson]

I have a mixed 150g mixed reef and SOME of my sps are not coloring up. My nutrients are low, near zero thanks to a larger refugium. For a long time now I assumed the reason why some of my sps were remaining brown was because my reef was mixed with a variety of soft corals etc. I run carbon and replace it weekly to help reduce any chemicals produced by the softies.

Lately, I have been wondering if the problem may be more caused by a lack of light. I run 175w iwasiki MH with VHO actincs. Would increasing to 250w color up these sps corals better? Or do you think it more of a mixed reef issue? I keep them near the top of the tank. The corals that are brown is a tri color acropora and a milli. I have a birds nest that is a dull pink at best. I also have a staghorn that is brown with a bluish hint around the edges. All of my corals are growing and other sps are colorful (green slimer, blue slimer, monti's)

Thanks,
Greg

 

[Snappy]

I used to run 175W's and thought I had pretty good colour, and on some acros I did. When I changed to 250w's I got way more color than before. I wish now I had gone with 400's

 

[tike]

Could be upgrading is the best thing to do considering you have a low nutrient load. How long has it been since you added the refugium? Whenever i have sps go brown it takes a few months for them to color up.You didn't mention if you're running one or two MH. if only one that definately is a problem since it is only covering about a 2 foot area. Anyway, I am thinking the upgrade to 250's would make your acros much happier.

 

[Kinerson]

Thanks for the responses. I've had the refugium longer then the sps's. I started getting into sps this past winter. I have two 175w mh on the 6' long tank, one on each end. The middle is where I tend to keep the softies as they require less light.

More thoughts would be appreciated
Greg

 

[smalltime]

I always thought higher wattage will drive the color out of the sps. Reefermaddness uses 1000w bulbs 20k or 400w 20k to get color as fast as possible. There in retail and they need fast turn around. Where alot of t-5 users depend on low nutrient tanks to get color out of sps.
I personally like 10k with vho suppletion.

 

[danno14]

If memory serves, that Iwasaki 175w has a very similar PAR (usable light output) as many well regarded 250w bulbs. I would check Sanjay's reference points before dropping the $$ on something that may or may not solve your issue.

What color were the corals, and under what bulbs, prior to acquiring them?

 

[Kinerson]

Danno14 your right about the Iwasaki 175w. They have a PAR around 70 which is similar to many of the 250w. I was looking at the xm 10000k 250w bulbs. They have a PAR of about 130.

The corals were under 400w bulbs before I got the frags and they were not brown. The Tri color acro was purple, blue, and green. The Mille was a deep red.

Greg

 

[Reeferdude]

I would think the 175s are adequate if they're in the upper areas of the tank. If it's a mixed reef maybe they're irritated by some softies?

 

[kevinpo]

The corals were under 400w bulbs before I got the frags and they were not brown. The Tri color acro was purple, blue, and green. The Mille was a deep red.

Hello,
I think you answered your own question
Something to try before you replace your lighting is to lower your bulbs as far as you can. The bird nest (S. hystrix) coloration is a very good indicator of lighting intensity. If you can lower the lights but not move the coral it should turn brighter/lighter pink in 7 days or less. If you cannot lower the lights, raise the S. hystrix up directly under the center of the halide to the highest point you can. Again it should lighten in less than 7 days. It is very unlikely (IMO/IME) that the other corals in the tank have an impact on the coloration of your corals.

For high light SPS corals I like to see a PPFD of at least 130 @18". For example an XM 10,000K SE bulb driven by a M80 ballast will give you a PPFD of 182 @ 18" plenty of HP to color any coral. Please note that lower light corals may suffer from so much intensity and careful placement will be required. Even high light corals that have darkened will need to be acclimated to sudden increases in light intensity.

HTH,
Kevin
Note: The above numbers were taken from Sanjay's data.
http://www.reeflightinginfo.arvixe.com/selectperformancedata.php

 

[Kinerson]

Thanks everyone.

Kevin- I can lower my light a good 6" before it gets wet If I do this, should I be overly concern about shocking some of the corals?

Do you think the XM 10000k SE 250W is a good choice or is there something better in the 250w catagory? From what I have seen on Sanjay's data the next bulb that still has some bluish color is the South Pacific Sunlight 250W 10000K SE 1 which drops in PAR to 85 (not much better then my current Iwasaki's 175w) but has a cct of 19000. The XM SE has a cct of 12000 and a PAR of 137.

Thanks so much everyone for the help,
Greg

 

[alazo1]

You would think adding another 175 in the middle would give more intensity all the way around. Your softies should be able to handle that, you think?.

Albert

 

[Kinerson]

Yeah Albert that is a good point. I have been trying to avoid this as a means of focusing the light where it needs to be. The sps are on each end and the softies are in the middle. If electricity was free then I would have been running three all along. Obvousily, I'm willing to up my electric bill to get the colors I'm after. I will consider that if I determin that light is the issue (it sounds like it is).

 

[Herefishyfishy]

For SPS, putting 175s on a 150 is a waste. Go for at least 250s if not 400s. You will be glad you did.

 

[kevinpo]

Hello Greg,
I really don't like to see halide bulbs closer than 4"-6" to the water surface as it can increase the likelyhood of them being splashed or you getting burned. If you can't get the corals to color up at that level then IMO it's best to:
Live with the colors you have.
Make sure the water is as clear as possible by running carbon and changing it frequently.
Place the coral as close to the surface as possible and directly under the bulb.
Install more powerful lights.

The Krystal Star SE 11,000K bulb driven by a PFO HQI ballast has a nice color (IMO) and will give you plenty of intensity (177 PPFD). NOTE: I have not personally tested the longevity of this bulb.

Adding a third 175W bulb will do little to increase the light intensity but the corals that are not located directly under the bulb will benefit by having better light 360 degrees.

Reflectors and height are so very critical. Be sure to check out Sanjay's work with reflectors/height here:
http://www.advancedaquarist.com/issues/mar2003/feature.htm

Look closely at Fig. 7 with the PAR numbers to the left of the grids. Notice the large PAR difference from 6-12" heights. Notice too that the area of very high intensity is only about 6" by 6" (Fig. 8) which makes placement of high light SPS corals critical.

HTH,
Kevin

 

[Kinerson]

Thanks for all your input guys.
Kevin, I appreciate your info as well. You mentioned the Krystal Star SE 11,000K bulb driven by a PFO HQI ballast. I want to make sure I understand this correctly. Is this a single ended lamp and a ballast designed for double ended lamps?

 

[Kinerson]

I guess I should make sure everyone knows the light fixture I'm using. It's a Hamilton 6' fixture capable of running up to 3 single ended MH lamps (175w currently) and 2 180w VHO's. It originally came equiped with 3-250w ballasts but I replaced them with 3-175w ballasts as an attempt to save on electricity and because at the time I didn't have high light needing corals. Things have changed and I now keep an assortment of sps as well as my original lps and softies.

Are there high end replacement reflectors that a 6' light fixture can accept or are the reflectors made for individual pendants?

 

[kevinpo]

Yes that is correct. I run HQI ballasts on all my mogul style bulbs. The HQI ballast overdrives the bulbs and increases their output as much as 20%. Of course you don't get anything for free. The life of the bulb is shortened by 2-3 months Electronic and pulse start type ballast fall somewhere between the standard magnetic and HQI ballast in PAR output and bulb life.

Regards,
Kevin

 

[Kinerson]

Interesting.

Thanks again