Why aren't my corals colorful?

TheCoralReef731

New member
All of my SPS corals are brown. Many were colorful when I recieved them, but they all turned brown. Is it because of my light? It is a 175w MH pendant. I had it suspended about 6 inches above the water, but I adjusted it to 12 inches today to see if the change could color up my corals. All my parameters are good. They are as follows:

Ammonia: 0 (I had some problems with this test. It was either 0 or .5, but considering it is an established tank and my nitrates are 0, I think it is 0)
Nitrite: 0
Nitrate: 0
Calcium: 380ppm
Alkalinity: 8.4 DKH
pH: 8.3
Temp: 80.5

Would my kinda low calcium levels affect the corals' color?

Any help is much appreciated. Thanks.

Peter
 
a 175 watt halide should be enough intensity for a 25 gallon tank. The distance seems adequate but you might want to drop the distance to about 8 inches.

As important as the wattage is the spectrum of the bulb. What is the Kelvin rating on the bulb and how old is it?

Everyone, myself included, has an opinion on what spectrum of light makes the corals look best. Some say 10,000 K with true actinic supplementation. Others like 14,000 K with no supplementation. Others like 20,000 K.

Also in order to keep them from browning out you need to acclimate them to the light you have. That is especially if your setup differs from the source. If you went to a LFS or another hobbyist (as opposed to mail order) ask about how the source runs their lights as far as time and how far from the corals.

Good luck.

Adam
 
adamjr - it is a 20,000K XM bulb. 2 months old. I didn't like the 10,000K bulb I had before. The corals were browning under the 10K also. Even if I didn't acclimate them to my light, wouldn't they recover? It has been multiple months for many of these corals and they have stayed brown for awhile. It is nothing to serious, because none have died yet.

Flint&Eric - what makes you say that the organic levels are too high? What does that mean? I don't have a phosphate test kit yet. I'll go out and buy one.
 
what is the flow like in your tank? Do you have more than just the return from the sump? Perhaps that is preventing your corals from being happy.
 
I too would guess that you issues are due to excess nutrients or phosphate levels. Those are two very commone causes of browned out sps.
 
anjof - the flow in my tank is very good. I have 500 gph from the sump and a 275 gph powerhead.

Flint&Eric - I just set up my RODI, and it is producing "high quality H20". However, the water that I used before that was not so great. It was RO water from Meijers. I am going to do a few water changes in the coming week to help.

I am not familiar with rowa and hanna. What are they? If they are chemicals, the answer is no. I don't add chemicals to my tank.
 
Hanna=digital phosphate meter (probably excessive for your needs IMO)
Rowa=phosphate absorbing media, used in a fluidized reactor/filter.

There are many variations of phosphate absorbing media..Phosban, PhosLock, Salifert has one...RowaPhos...etc. All do the same thing essentially.

I would agree that high organic levels are potentially an issue. Put on a phosban reactor (or whatever phosphate media you choose to use). Start the reactor up very slowly, i.e use 1/2 to 1/3 of the amount of media they recommend (you don't want to go from high phosphates to 0 in a few hours, that will be more damaging to the corals). I'd also run some carbon for good measure.

Check the usual on-line store and the local shops for phosban/phosphate reactors.

BTW, you say your RO is producing "high quality H2O"...How do you know this? Have you checked it with a TDS meter?
 
<a href=showthread.php?s=&postid=7607593#post7607593 target=_blank>Originally posted</a> by TheCoralReef731
I'm not entirely sure. I don't have a TDS meter. Could I borrow someones?
You really need a TDS meter. It's an absolutely necessary accessory to an RO/DI unit, IMHO.
 
we can go on and on about lights, but personally speaking, i like the 10K bulb with actinic supp to it.....my corals keep there color and grow like mad......i dont think the 20k has the speck you want to keep the coral coloration or growth that we all desire...again only my opinion.....to each the own really. But a 20K bulb looks nice, but really thats it.

Your specs do look good, good flow, etc....

how long is your light cycle? 8hr? 10hr?
do you run actinic bulbs as well as the 20K MH?
do you add supplements?
H20 changes? how often?

HTH
 
Racenrich - Great point. I never thought about how my light cycle could affect it. I only run the MH, and no actinics. I chose 20K over 10K because I did not want to have an elaborate light system (20K has the actinics built in). Just two lights, MH and moonlight. The MH runs for 12 hours each day. Thanks for pointing that out. I am going to change it to 9 hours.
 
Hello
I'd try a different light, with more PAR. Corals can turn brown as the zooxanthellae (they are mostly brown/green) multiply looking for more light?
 
Hello
In the 175 watt, I like the Ushio 10K, and the new Iwasaki 13K/? looks like a good bet also. I havn't checked them all, but the 20K bulbs have the lowest PAR values of the bulbs that I have measured... What ballast are you using?
 
Thanks for all the good advice everyone.

I just recieved my phosphate test kit from USPS today, and I took a test. My phosphates are around 1.25ppm.

Instead of purchasing a phosphate reactor, couldn't I just skim more? My skimmer turns off half the day because it is in my bedroom and it is quite noisy at night. I could adjust it to skim more often.
 
<a href=showthread.php?s=&postid=7635996#post7635996 target=_blank>Originally posted</a> by TheCoralReef731
My phosphates are around 1.25ppm.

Are you sure you're reading that kit right? Everything would likely be very dead if that were the case. .03 ppm (or mg/L...same thing) is considered high phosphates and corals start dying. You're talking levels 41 times that high.

What test kit is it?

Also the 1/2 time skimmer is definitely not helping things. If you're only going to be able to run that 1/2 time, I would highly recommend a phosphate reactor to compensate for the downtime. Even with 24/7 skimming, you will not likely get most of the phosphates out (I have a huge skimmer and I still pull phosphates out with media).

Skimming also adds oxygen to the system. My assumption is that you are turning the skimmer off at night which is probably making the problems worse. Photosynthesis stops at night without light, so CO2 levels naturally start climbing...Now you've turned off the fresh oxygen supply which doubles up the issue. Do you notice a heavy pH swing during the night time?
 
Thanks for the advice mike!

The brand is Aquarium Pharmaceuticals. I did read it correctly, and it is at 1.25 ppm (mg/L). The color card goes all the way up to 10ppm. I will try another test to see if this was just a fluke.

The reason why I can skim half the time is because my skimmer is rated for 75+ gallon tanks, and mine is only 25 gallons. Skimming half the time still leaves me with a 12.5 gallon buffer (75 divided by 2 minus 25).

My pH never swings. My alkalinity has always been on the high side, and my pH has always been a constant 8.3. I don't understand how the oxygen levels could affect my phosphates.

Also, what reactor (not so expensive) would you recommend?

Thanks,
Peter
 
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