Tank Gone Yellow!

[chaost]

Hi,

I have had a marine tank for 4 years now, live rock and 3 fish, thats it.

I decided to upgrade lighting to a 250w MH and start getting some coral on the go. Bought on ebay, all okay, excpet for a massive shadow in the tank. So, went back to ebay and bought an Arcadia unit 2 x 150. Great! No shadow, all perfect! I also got 3 maxi-jet 1200 in wtih the deal and so added them to the tank as well.

(tank is 50gls and is at my office )

Anyway, i came in on Monday and to my shock, the tank gone yellow! Newly purchased live rock - yellow, substrate - yellow.

I have done water tests - all seems excellent.

Anywon have any ideas what could have caused this, and how i can get rid?

Many Thanks
Andre

PS> Great forum btw.

 

[Pandora]

Hi chaos,
<img src="/images/welcome.gif" width="500" height="62"><br><b><i><big><big>To Reef Central</b></i></big></big>

I have a thought that this may be an algal bloom. These are usually green, but may have a yellow tint when seen under very yellow lights (and some algaes are less green than others, such as diatoms can have a distinctly yellow tint, or algae that has lost some of its chloroplasts). The idea that this is algae makes sense, because you have recently upgraded your lighting quite a bit. I would do a small percentage water change for now and possibly decrease your photoperiod (how long is it now)? And what kinds of corals do you have in the tank now? Corals can help compete for resources, since they have zooxanthellae within them (a type of algae). Have you measured for things like phosphate and nitrate? Just throwing a few ideas out there.

 

[dhoch]

What kind of bulbs do you have in there Andre? (i.e. what frequency)...And how old are they?

Why Pandora is probably right, lighting deterioration and frequency can add to the affect (low K bulbs 6000K are more yellow than higher K bulbs, also bubls frequencies shift as they are used over time).

Dave

 

[chaost]

Thanks guys,

I have 14K bulbs, but am waiting on 20k coming. Phostphate and nitrate test okay - photoperiod 8hr MH, 12 hrs actinic. No corals yet, only live rock (but most of it 4 years old).

Have done 15% water change - will wait and see!

 

[MarksReef]

Are you running carbon? If not, it will help alot.

 

[Pandora]

That's a good thought, dhoch. Bulbs that are older shift their spectrum over, which is why people tend to need to replace them after a period. I've also noticed that they grow algae better and corals not as well after they've aged. How old are the bulbs in this one?