Potassium (K) 365 ppm

[Fringe09]

A few of my Montiporas have and are going through STN.

I haven't been able to find any montipora eating nudibranch. I have inspected the corals when the lights are out and I see nothing moving on them. I am told these type of nudibranchs are easy to see. So I'm ruling this out.

I neglected testing Magnesium and it dropped to 1200. Raised it back to 1350.

I read somewhere that low Potassium might also cause STN. I tested twice with Salifert test kit. 370 and 360. Let's call it 365. Natural seawater is approximately 400 ppm.

Should I raise mine to 400 ppm or 365 ppm okay for a reef tank?

 

[Larry L]

What does the STN look like? From what I've seen, Monti-eating nudibranchs tend to leave white patches here and there, as opposed to a bottom-up progression (like you see on Acros that STN) or an overall bleached-out look. Potassium at 365 ppm is a bit low but also in my experience nothing that would cause problems. My Montis seem to be very sensitive to alk swings, especially the Monti caps - do you know how stable your alk has been?

 

[Fringe09]

What does the STN look like? From what I've seen, Monti-eating nudibranchs tend to leave white patches here and there, as opposed to a bottom-up progression (like you see on Acros that STN) or an overall bleached-out look. Potassium at 365 ppm is a bit low but also in my experience nothing that would cause problems. My Montis seem to be very sensitive to alk swings, especially the Monti caps - do you know how stable your alk has been?

No white patches. The Cap started to STN from the outer edge. The digitata started to STN from the base.

My Alk is hovering between 7.9 to 8.1. It was in the low 7s in August. Brought it up slowly.

 

[Anirban]

Your Potassium is possibly not causing the STN. 365 is not that low. You can raise it but thats not the cause. Whats the nutrient level?

 

[Fringe09]

Your Potassium is possibly not causing the STN. 365 is not that low. You can raise it but thats not the cause. Whats the nutrient level?

Alk: 7.9-8.1
Ca: 410-420
NO3: 0
PO4: .04-.07
Mg: 1350-1375
Salinity: 1.025
pH: 8.1-8.3

 

[Anirban]

Bring the nitrates up. Its possibly is doing more harm than your potassium.

 

[Fringe09]

Bring the nitrates up. Its possibly is doing more harm than your potassium.

I’ve been wanting to raise it for a while now.

Brightwell makes a product called NeoNitro Nitrogen that does it. Try it?

 

[Anirban]

you can dose potassium nitrate too but slowly.

 

[Fringe09]

you can dose potassium nitrate too but slowly.

Gonna try it and see how it goes.

 

[Randy Holmes-Farley Verified Community Expert]

I do not know if it is a cause or not, but I would raise it. It is cheap and easy to do.

I would not use potassium nitrate unless you need substantial nitrate. Potassium chloride is, IMO, usually better.

 

[Fringe09]

I do not know if it is a cause or not, but I would raise it. It is cheap and easy to do.

I would not use potassium nitrate unless you need substantial nitrate. Potassium chloride is, IMO, usually better.

Hi Randy,

To raise Potassium, I'm going to use Potassion from Brightwell which has Potassium sulfate and Potassium chloride.

As my NO3 is 0 and PO4 is around 0.04-0.07, I'm going to use NeoNitro also from Brightwell.

 

[Randy Holmes-Farley Verified Community Expert]

Hi Randy,

To raise Potassium, I'm going to use Potassion from Brightwell which has Potassium sulfate and Potassium chloride.

As my NO3 is 0 and PO4 is around 0.04-0.07, I'm going to use NeoNitro also from Brightwell.

That seems like a fine plan. I’m not a fan of many Brightwell products, but hopefully this simple one is ok. Lol