Potassium and Algae Growth

perrdav · 09/18/2012, 12:00 AM

So I was at my lfs this weekend and we got to talking about green hair algae and he recommended dosing potassium to kill gha. I've never read anything that would indicate that this would help, but I thought I would ask here to see if anyone has any info on this.

I don't test for potassium so I don't want to go dosing anything blindly. And to be honest, it seems like algae might use potassium for growth like other plants, so wouldn't increasing it lead to MORE algae? Thanks.

bertoni · 09/18/2012, 12:03 AM

There's about 400 ppm of potassium in saltwater. I have never heard that adding more will discourage algal growth. How much was he talking about dosing?

perrdav · 09/18/2012, 12:10 AM

I believe he said up to 700 ppm could be done safely. Unfortunately I didn't have a lot of time to pick his brain on the reasoning behind the increase.

incognitus · 09/18/2012, 12:45 AM

I believe adding a salt to aquarium water can kill something in it. When I increased magnesium for the first time a white carpet that growed below a rock disappeared in just one day. It was a little switch (25 mg/liter) but a fast-acting killer.

I don´t know about potassium/green hair algae though.

bertoni · 09/18/2012, 12:55 AM

Well, it might work. I'm skeptical, though.

kipper31 · 09/18/2012, 03:31 AM

Raise your potassium to 700 ppm and say by ,by corals.Most SPS will RTN.Dont dose unless you can test.I think increased pottasium would lead to more Algea,I'm very surprised a LFS would reconmend raiseing to 700.

gmneil · 09/18/2012, 04:43 AM

i think they meant raise your mag, kent tech m seems to work at killing gha when you use it to raise your mag to very high levels

edgey · 09/18/2012, 05:40 AM

The algae scrubber crowd is looking at potassium depletion as a possible cause of diminished algae growth. The thinking is maybe K is a limiting factor, preventing P and N from getting mopped up with algae.

I'd be leary of adding anything above NSW levels.

perrdav · 09/18/2012, 01:32 PM

Thanks for the replies. I wasn't planning on dosing anything, but thought I'd ask about it due to curiosity.

Psyops · 09/18/2012, 05:46 PM

Maybe he said Magnesium. I keep my levels at around 1500 ppm and I have not had any GHA for 2 yrs. I accidentally increased my levels back then due to a faulty Mg test kit.

I am not as experienced as some here on RC, but am skeptical about K dosing.

chungsl · 10/18/2017, 02:41 AM

Quote:

Originally Posted by edgey

The algae scrubber crowd is looking at potassium depletion as a possible cause of diminished algae growth. The thinking is maybe K is a limiting factor, preventing P and N from getting mopped up with algae.

I'd be leary of adding anything above NSW levels.

I dose potassium to 430ppm ,i found that less less microalgae is on the tank glass.

09/18/2012, 12:00 AM	#1
perrdav Registered Member Join Date: Oct 2011 Location: S Carolina Posts: 11	Potassium and Algae Growth So I was at my lfs this weekend and we got to talking about green hair algae and he recommended dosing potassium to kill gha. I've never read anything that would indicate that this would help, but I thought I would ask here to see if anyone has any info on this. I don't test for potassium so I don't want to go dosing anything blindly. And to be honest, it seems like algae might use potassium for growth like other plants, so wouldn't increasing it lead to MORE algae? Thanks.

09/18/2012, 12:03 AM	#2
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	There's about 400 ppm of potassium in saltwater. I have never heard that adding more will discourage algal growth. How much was he talking about dosing? __________________ Jonathan Bertoni

09/18/2012, 12:55 AM	#5
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	Well, it might work. I'm skeptical, though. __________________ Jonathan Bertoni

09/18/2012, 04:43 AM	#7
gmneil Registered Member Join Date: Mar 2008 Location: buffalo, ny Posts: 1,191	i think they meant raise your mag, kent tech m seems to work at killing gha when you use it to raise your mag to very high levels __________________ you always lose money chasing women, but u never lose women chasing money.. Current Tank Info: the keeper of clowns,, to many tanks to list

09/18/2012, 05:46 PM	#10
Psyops Still Learning Join Date: Mar 2011 Location: Where my wife decides Posts: 714	Maybe he said Magnesium. I keep my levels at around 1500 ppm and I have not had any GHA for 2 yrs. I accidentally increased my levels back then due to a faulty Mg test kit. I am not as experienced as some here on RC, but am skeptical about K dosing. __________________ GOT REEF! One tank short of a trial separation. Current Tank Info: 180 Gallon reef. Just starting to convert to mainly SPS.

09/18/2012, 12:10 AM	#3
perrdav Registered Member Join Date: Oct 2011 Location: S Carolina Posts: 11	I believe he said up to 700 ppm could be done safely. Unfortunately I didn't have a lot of time to pick his brain on the reasoning behind the increase.

09/18/2012, 12:45 AM	#4
incognitus Registered Member Join Date: Dec 2009 Location: Spain Posts: 63	I believe adding a salt to aquarium water can kill something in it. When I increased magnesium for the first time a white carpet that growed below a rock disappeared in just one day. It was a little switch (25 mg/liter) but a fast-acting killer. I don´t know about potassium/green hair algae though.

09/18/2012, 03:31 AM	#6
kipper31 Registered Member Join Date: Aug 2009 Location: australia Posts: 92	Raise your potassium to 700 ppm and say by ,by corals.Most SPS will RTN.Dont dose unless you can test.I think increased pottasium would lead to more Algea,I'm very surprised a LFS would reconmend raiseing to 700.

09/18/2012, 05:40 AM	#8
edgey Registered Member Join Date: Feb 2012 Posts: 37	The algae scrubber crowd is looking at potassium depletion as a possible cause of diminished algae growth. The thinking is maybe K is a limiting factor, preventing P and N from getting mopped up with algae. I'd be leary of adding anything above NSW levels.

09/18/2012, 01:32 PM	#9
perrdav Registered Member Join Date: Oct 2011 Location: S Carolina Posts: 11	Thanks for the replies. I wasn't planning on dosing anything, but thought I'd ask about it due to curiosity.