View Full Version : No NO3, PO4; dosed KNO3 - GHA explosion

06/22/2017, 10:26 AM
So I tried a KNO3 experiment to get my nitrates up to see if I could color up my SPS. After just short time (few days) the result I had was a GHA explosion where almost none was in my tank present before the dose. It's hung around for a few months now.

I've read up on carbon dosing and have tried to do that off and on with the theory that the bacteria would feed my corals - no big change, really, except some cyano here and there. When I first cranked up my tank I had NO3 readings and initially did that to bring them down. I've stopped since NO3 has just disappeared.

It's been months since I've had any NO3. While my corals are growing they are losing color. I know the basics - been keeping my parameters as stable as I can for a while.

I also tried GFO to see if it would absorb the PO4 presumably in the water that we can't detect to battle the GHA. REALLY made the coral look bad, so I stopped with coral improvement on the way.

So now the GHA is holding rather steady. I'm really not sure that I starve the tank as I dose with phyto (about a teaspoon) every day and feed the fish generously I think. I've had vermetid snails all over so that's further evidence I'm feeding enough in my opinion. I BELIEVE the GHA has choked them out as they have subsided a bit.

Is my bacterial fauna off balance? I see some strands of dino (I THINK) when I feed - really hang off the urchins. I've tried algae scrubbers in the past in different configs and really couldn't get any to take root. I just grew cyano.

I've done a Triton test to see what they said - results were NO3 and PO4 undetectable (figure that) and that my iodine and strontium were low. Otherwise everything was spot on.


06/22/2017, 01:41 PM
How is the GHA going? Im suspecting you did an overdoes for everything.

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06/22/2017, 02:49 PM
How did you dose it, i.e. what what your regimen?

06/22/2017, 03:39 PM
Sure. Mixed up 3L bottle KNO3 from a Spectracide container. Mixture supposed to raise my 200Gal system 1 PPM at 8 mL.

First dose was 10 mL, with NO3 measured every day. Right after dosing (same day) NO3 was .75 PPM per Red Sea. Each day NO3 decreased until 3 days later it read 0 and I dosed 5 mL. within 9 days I noticed more GHA on rocks, then I started carbon dosing again very slowly (1 mL/day).

I never dosed more than 2 times of KNO3. After that GHA started in and I stopped it and kept the carbon dosing on low and started GHA abatement program. Aggressive water changes, GFO.

I also noticed a bit of snow on the rocks - maybe I'm not getting enough of that off the rocks and in suspension to remove? How can you tell enough is enough?

I did note more PE and nicer green color in my chalice (he's only green when he's really happy I think). I've stopped GFO and the GHA has seemed to subside a bit (Iron??) and I'm getting a bit more colors back into some of the acros - but not anywhere I need to be.

06/22/2017, 04:59 PM
Reason I ask is I had the same problem. I waited out the GHA and tried again but going SUPER slow, like 1/4 speed and it worked great.

I can only guess that the tank couldn't process the extra nutrients and the algae was more up to the job than the bacteria and corals were.

I also had a pale SPS tank. I'd recommend getting GHA under control and trying again but going SUPER slow

06/23/2017, 03:55 PM
Well, that seems reasonable. So what's super slow? dosing enough to raise NO3 1 PPM isn't slow? If it isn't that's fine, just want to be sure I'm on the right page.

Annnd...would you then ALSO carbon dose to up the total bacteria load or is all this counter productive?

06/23/2017, 04:13 PM
I used a spoon from the Red Sea test kits. It's a tiny spoon, also used on brs reef chili. And did one level spoon per week and didn't chase numbers. My N03 stayed at zero for weeks but I didn't chase numbers and saw results in the corals.

I stuck to that until I saw my N03 hit about 5ppm which took a bit.

I'm not saying this is a perfect solution or the absolute way to go. But I did have good results by luck doing this

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06/24/2017, 06:04 PM
Well that is a heck of a lot slower than what I did. Might try going much slower.

06/30/2017, 05:05 PM
Sounds to me you had a lot of po4 and the lack of P3 was hiding that.

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