Green Water and P?

[krisw]

Well, after years of avoiding the imfamous green water, it appears that after tearing down my 75G to replace the substrate with Soilmaster, and then bringing it back up, overzealously dosing in eager anticipation of righting a tank that's been horribly wrong for too long, I've gone and messed it up again.

So, I recall some conversation about fixing green water by dosing more phosphate, but I can't seem to locate any information on this on our or other forums. Can someone clarify whether I'm just making this up, or whether there's a methodology to it?

Currently, I'm just blacking out the tank, while running the HOT Magnum with micron filter. If adding phosphate will help excelerate the recovery, I'd be more than happy to dose it!

[Jeff120]

Sean is the one that suggested that, I tried it in my 29 but got a little scared about 2-3 days and didnt notice a difference. You need to dose PO4 very high, the higher the levels the better. I would stick to the blackout/HOT for now. The HOT should clear it up

[krisw]

Thanks Jeff! How long did you have to black yours out with the diatom filter before it cleared up?

[Jeff120]

I didnt black it out at all, the diatom cleared the water in about 20 min!

[krisw]

Huh... Those diatom's must be better than the HOT micron filter. I've had it running for a day or two with the lights going. It was only getting worse. So, I'm in blackout period now. I'll probably try adding some more PO4 to see if that'll help things along.

[Ghazanfar Ghori]

Kris - try a flocculant along with running the HOT micron - it should elminate
most of it fairly quickly - though it may come right back since you're addressing
the symptom and not the problem.

[krisw]

Forgive the ignorance... But what is a flocculant, and where can I find such a thing?

[Jeff120]

Water clarifier, Petco will have some. You could also try some diatom powder in the HOT

[krisw]

So... Would the best thing to be to use a flocculant, other the HOT to run for a day, then do a water change, and rebalance the water by dosing "correct" amounts of ferts?

[DelawareJim]

Kris;

I'm not sure if the clarifier will kill the algae.

Depending on the type you get, you will either need to vacuum the gravel or skim the surface after the clarifier does its thing. The flocculant will cause the green water algae cells to aggregate into clumps that will then either sink to the bottom into the substrate or float to the surface. Unless you vacuum the gravel there is the possibility they may come back again if conditions are right.

I've only ever seen it used in ponds.

Cheers.
Jim