Potassium Solution

[msderganc]

Hi Randy,

Just wanted to double check my math before I make up my solution. I posted on another thread about potassium and some of my millepora (including my red planet). I isolated it down to Seachem Flourish Potassium. Dosing just 2ppm caused a number of my millepora to retract polyps and not look happy. So I'm making a solution of potassium chloride as follows:

Using Now Potassium Chloride powder, it says that 700mg will provide 365mg Potassium. From that I'm trying to create 500ml of solution that will increase my 220g net volume system (833 L) by 2ppm for each 20ml I dose.

Given that, I think I need 2mg/L * 833L, 1666mg P per 20ml. Converting to the powder amount, I need 700mg Powder/365mg P*1666mg P, or 3194 mg Powder per 20ml. This equates to 79.9g plus enough water to make 500ml.

Is that correct?

Thanks,
Matt

 

[Randy Holmes-Farley]

Yes, that looks correct.

I don't remember seeing the other thread. You believe that 2 ppm potassium addition with Seachem Flourish Potassium caused a problem with the corals? THe only way i could see that happening is if it wasn't exactly what it claimed to be for some reason.

 

[msderganc]

Yes, that looks correct.

I don't remember seeing the other thread. You believe that 2 ppm potassium addition with Seachem Flourish Potassium caused a problem with the corals? THe only way i could see that happening is if it wasn't exactly what it claimed to be for some reason.

Yes, 10ppm caused three of my millepora to retract polyps for nearly a week. 2ppm caused them to pull back a little bit, although my Red Planet is pretty much fully retracted.

The supplement I used is this http://www.amazon.com/Seachem-116046305-Flourish-Potassium-500ml/dp/B0002APILO which is supposed to be just Soluble Potash (K20 at 5% solution). I used 183ml the first time for a 220g net volume, which was in line with the recommendation on the bottle to increase by 10 mg/L.

 

[Randy Holmes-Farley]

OK, a bit surprising. I have to wonder if the problem was an impurity rather than the actual potassium or sulfate main ingredients.

Have you seen anyone else with this problem?

 

[msderganc]

OK, a bit surprising. I have to wonder if the problem was an impurity rather than the actual potassium or sulfate main ingredients.

Have you seen anyone else with this problem?

I haven't, and I thought it was weird myself. I'm going to try that stock solution and see how it works. That should help determine whether it's the potassium or some impurity issue with the Seachem.

 

[Randy Holmes-Farley]

OK, let us know what happens.

 

[msderganc]

So using 20ml (2ppm for 220g) of my solution, there was no reaction from the corals. No issues whatsoever. I'm guessing either there's a contaminant in the Seachem Flourish, or something about the Potash is aggravating the corals.

 

[Randy Holmes-Farley]

So using 20ml (2ppm for 220g) of my solution, there was no reaction from the corals. No issues whatsoever. I'm guessing either there's a contaminant in the Seachem Flourish, or something about the Potash is aggravating the corals.

FWIW, the Seachem product does not contain potash. That is just a legal description required for quantifying potassium fertilizers (the equivalent amount of potash), as they explain on the Seachem web site. It contains potassium sulfate.

 

[Silentreefer]

Old post but the seachem flourish potassium has 1.5 pentanedial? which is something like formaldehyde it's on the label I googled it and read enough to not want to try it in my tank lol works great with my freshwater plants though