carbon adding phosphate

[james37128]

Has anyone had experience with adding carbon then having a pretty big algae bloom? I am thinking that the carbon added alot of phosphate to the water, which then resulted in the unwanted algae taking off. I ran the carbon for 3 days, thats when I noticed (wow, algae is growing on the glass A LOT faster than normal). I got the carbon in Japan so it's a Japanese brand. What do you guys think? Am I on the right track? To be noted, I didn't have a phosphate test until today, and yes it is high...

[Boomer]

IMHO no. People just like to use carbon as their excuse to blame their high PO4 on :)

Phosphorus: Algae's Best Friend
http://www.advancedaquarist.com/issues/sept2002/chem.htm

Phosphate and the Reef Aquarium
http://reefkeeping.com/issues/2006-09/rhf/index.php

Nitrate in the Reef Aquarium
http://www.advancedaquarist.com/issues/august2003/chem.htm

[jdieck]

You can test the carbon by letting it soak overnight on RO/DI water then test the water for phosphate.
All carbons usually leach some phosphate but it is minimal on carbons for aquarium use.
If you measure more than 1 ppm in the RO/DI water you soaked the carbon in I would look for another brand.
BTW even if the carbon is low in phosphate I usually let it soak over night and change it's water a couple of times before putting it in the aquarium, that helps with removing some of the phosphate out of the carbon.

[packer]

Sounds like the carbon cleaned up the water ( clear-took yellow out) and more light penetrated to cause algae growth.

I would ditch the unknown carbon and get a known decent brand just to be safe.

[james37128]

I think it may have been a combination of the 2. I was running it on the system not because of yellow water, I added some new corals so if they were letting away any chemicals from stress or what not. I added the carbon to soak them up. In particular a toadstool that was looking pretty bad after I added it, I didn't want it killing off anything else I have. I do plan on getting some new carbon, but ran out and ran to the store real quick to get basically a quick fix/prevention. I think just for grins I will still test this stuff to see if its the culprit with a day soaking in RODI. I am thinking about how much water/ how much carbon to put in the mixture. I want to dilute it enough to see if there is a lot of phosphate, but not too much that I can't read it if there is only a little.

[jdieck]

<a href=showthread.php?s=&postid=11981857#post11981857 target=_blank>Originally posted</a> by james37128
I am thinking about how much water/ how much carbon to put in the mixture. I want to dilute it enough to see if there is a lot of phosphate, but not too much that I can't read it if there is only a little.

Use about 11/2 the volume of carbon. Say if you use 1/4 cup for the carbon use 1/2 cup of water. If it is too much phosphate for your kit you can dilute the sample with 50/50 RO/DI test again and multiply the result by 2.
Remember to rinse the carbon before the test same way you would if you were to use it in your tank.