Corals loosing colour

[CARLIN]

Hi Guys,

I'm knew to this forum so i hope someone can help me out.

I have been noticing over past few weeks my corals have been losing thier colour.
They are going to brown, like my SPS coral was pink and after few weeks is going too but looks very healthy.

Thier was one question i thought and that was my lights and they have been running for about 8months now and 10hrs a day.
i'm running the arcadia 3 series.

My tank is 120 gallons inc sump
I have checked my water readings and this is what i have got showing

Nitrate 10
Nitrite 0
Ammonia 0
Alk 8Dkh
Calcium 400ppm
Phosphate 0.03ppm
Ph 8.2
Salinty 1.026


I also run carbon and Rowaphos in the sump and change this every 4wks.
Water changes are done every 4wks with 30% change.

I'm just in puzzle now any info would be grateful

Cheers

Rob

[gws76]

I had a problem with browning before due to lighting. What kind of lights are you running? I'm not familiar with the arcadia 3 series.

I also change my carbon out every two weeks. How often are you changing the carbon?
Are you changing the water once every four weeks or is that a total 30% over a four week period? IMO, I would do a water change once a week, about 7.5% per week.

[CARLIN]

Hi Mate,

these are metal halides http://www.arcadia-uk.info/product.php?pid=5&mid=10&lan=en

I do full water change 30% every wks

also i change the carbon and that at the same time

[gws76]

???
I'm at a loss. How old is the tank?

Your lighting should be sufficient, maybe the bulbs need replaced.

[CARLIN]

My tank is 10month old

[gws76]

Still at a loss. The only reason I've ever had coral brown out was insufficient light. I had a pink birdsnest brown out and a monti cap brown out due to using a combo of pc lighting and t-5. As soon as I put them under all t-5's they colored back up in a months time.
Under metal halides you should have plenty of lighting. Unless the bulbs are past their life of productive light.

[Michael]

double check the phos reading, also what flow have you got in there,

[CARLIN]

My Phospate is fine i know that for def because it has been tested few days ago and done by local shop too.

The water flow i'm runing two Hydro 3 850GPH, also my water flow from the sump.

[WinnipegDragon]

Yeah way too little flow for a 120g SPS tank. I'm going to be running at least 4,800gph in mine.

[Haggis Catcher]

Hi, I am relatively new to the reef hobby and new on Reef Central, but I notice you havent posted an Mg reading? I know mag has an important part in corals

[Michael]

<a href=showthread.php?s=&postid=13288892#post13288892 target=_blank>Originally posted</a> by CARLIN
My Phospate is fine i know that for def because it has been tested few days ago and done by local shop too.

The water flow i'm runing two Hydro 3 850GPH, also my water flow from the sump.

looks like your turning over 12-15 times the tank flow per hour then, not sure if this lack of flow would cause your corals to go brown, sk8r maybe able to help there, however id suggest increasing flow to at least 20 times even up to 30 times

[crvz]

Coloration of corals is a result of many factors, including too much/too few nutrients in the water, intensity of lighting or duration of photoperiod, flow may play an indirect part of it, but I can't say it's the reason. Usually when I hear that corals are turning brown, it's a result of too many nutrients in the tank. Regardless of what the phosphate test showed, you could very well have excessive levels. Test kits test a very limited range of free po4 in the water, giving no insight to anything bound in algae or substrate, etc.

One way to counter-act the browning of corals is by providing more light, which will trigger the zoox to burn through more nutrients, which often results in better perceived colors. Though this is kind of a bandaid, as you'll want to fix the cause of the problem.

[bach2pilot]

Are you using RO water? How old are your bulbs?

[CARLIN]

Hi Guys,

Thanks for all your replies.

My lights are on for 10 hrs a day and they are 8mnths old from new.

I have always used RO water

So do i need to change my Rowaphos more often or add more to the sump?

My tank is 8months old now and this is the first time i have had any problems with corals.

I will get new bulbs for my lights and see how that goes first, i will let you know how i get on.

Thanks guys.

[CARLIN]

Just quick question how long do you leave your lights till you replace the bulbs?

[Michael]

<a href=showthread.php?s=&postid=13294349#post13294349 target=_blank>Originally posted</a> by CARLIN
Just quick question how long do you leave your lights till you replace the bulbs?

just changed my t5s, they were 8 months old, however a year is probably fine possibly even longer, are you anywhere near ilkeston:)

[CARLIN]

I'm from Alfreton, derbyshire buddy

[crvz]

did you say what kind of bulbs they are? If they're MH, you may be due for a change.

[dancewithethan]

IME, too much Iodine in the tank can cause carol to lose color.

[rogergolf66]

I would go with new bulbs and see if any one local has a hanna meter to test phosphates with as it is one of the few testers that will give you accurate readings on phosphates.

Roger

ps the low flow should not cause the browning but you need alot more flow in that thing. powerheads only I move over 4,000gph in my 125 and if I turn the powerheads up to 100% I can move over 8,000 GPH