Tested potassium today to find it down at 320

[rock_lobster]

delete

 

[Randy Holmes-Farley Verified Community Expert]

I would not say it is inevitable. To be honest, I'm not sure why there aren't just as many tanks rising in potassium as dropping, since there's no reason that foods do not have as much potassium in them (relative to N and P) as do tissues formed in the tank. Maybe it is lost in processing...

When companies give max rates, it often assumes you are not measuring things.

I'd boost it a lot more than that.

 

[JimWelsh]

Their web page for this product says more or less everything the OP said above, but it also specifies that the product is 49% potassium. Based on that, their number of 1.7 PPM is, by my calculations, incorrect. It should be 2.7 PPM. Here's the math: 49% of 5 grams in 8 oz of water is 2.45 grams of potassium in 236.6 mL of water, or 10.36 mg of potassium per mL. That 10.36 mg of potassium divided by 3.785 liters of water = 2.74 mg/L.

 

[TheEngineer]

I used this product to raise my potassium:

NOW Potassium Chloride Powder, 8-Ounces https://www.amazon.com/dp/B00028M02Q/ref=cm_sw_r_cp_api_XGPsAbCPT5NNY

It is much more potent (and less expensive) than the reefing sources.

 

[JimWelsh]

Straight potassium chloride is 52.4% potassium. Straight potassium sulfate is 44.9% potassium. Most reef products (such as Brightwell's) would likely be a mixture of these two in a ratio designed to maintain NSW SO4:Cl ratios. While I'd hardly call 52.4% "much more potent" than Brightwell's 49%, it is very likely much less expensive to use straight potassium chloride, as long as the SO4:Cl ratio doesn't get too out-of-whack.

 

[Randy Holmes-Farley Verified Community Expert]

Their web page for this product says more or less everything the OP said above, but it also specifies that the product is 49% potassium. Based on that, their number of 1.7 PPM is, by my calculations, incorrect. It should be 2.7 PPM. Here's the math: 49% of 5 grams in 8 oz of water is 2.45 grams of potassium in 236.6 mL of water, or 10.36 mg of potassium per mL. That 10.36 mg of potassium divided by 3.785 liters of water = 2.74 mg/L.

It is remarkable that Brightwell makes so many similar mistakes.

 

[TheEngineer]

Potent was the wrong word It takes less of the food grade stuff to have the same effect. The potassium chloride is 365 mg of potassium per 1/8 tsp.

Using the numbers from Brightwell, 1/4tsp raises a gallon of water by 129ppm. 1/4 tsp of the food grade stuff raises it 193ppm. That’s almost 50% more bang for the volume added. I’d venture to say the food grade is probably significantly cheaper. I got 8 oz for $4 shipped.

 

[JimWelsh]

Ahhh. I see. "Dense" was the word you were looking for.

 

[TheEngineer]

Ahhh. I see. "Dense" was the word you were looking for.

You making fun of me!? Lol (joking)

Dense is a better word

 

[Steved350]

Lol. Good info

 

[rock_lobster]

Their web page for this product says more or less everything the OP said above, but it also specifies that the product is 49% potassium. Based on that, their number of 1.7 PPM is, by my calculations, incorrect. It should be 2.7 PPM. Here's the math: 49% of 5 grams in 8 oz of water is 2.45 grams of potassium in 236.6 mL of water, or 10.36 mg of potassium per mL. That 10.36 mg of potassium divided by 3.785 liters of water = 2.74 mg/L.

Makes a lot of sense. I've actually tested low potassium a few times over the years and when I dosed the correct amount over a few week period I always noticed that my final potassium was much higher than the product stated it should be according to the dosing. 2.7ppm/ml is pretty much exactly the gain that I got from dosing to replenish.

 

[rock_lobster]

I used this product to raise my potassium:

NOW Potassium Chloride Powder, 8-Ounces https://www.amazon.com/dp/B00028M02Q/ref=cm_sw_r_cp_api_XGPsAbCPT5NNY

It is much more potent (and less expensive) than the reefing sources.

I bought the 300g potassion still pretty cheap at 10$ and it should last me at least a decade haha. Probably longer now that I find out that their dosing is wrong.

 

[rock_lobster]

I would not say it is inevitable. To be honest, I'm not sure why there aren't just as many tanks rising in potassium as dropping, since there's no reason that foods do not have as much potassium in them (relative to N and P) as do tissues formed in the tank. Maybe it is lost in processing...

When companies give max rates, it often assumes you are not measuring things.

I'd boost it a lot more than that.

I feed quite heavily and I do consistently lose potassium. I calculated the rate to be .33 ppm per day over the last 4 years and that is also including the dosing of red sea ABCD and some very small water changes maybe 20% per year total.

 

[Randy Holmes-Farley Verified Community Expert]

I feed quite heavily and I do consistently lose potassium. I calculated the rate to be .33 ppm per day over the last 4 years and that is also including the dosing of red sea ABCD and some very small water changes maybe 20% per year total.

Ever check your new salt water at the salinity you use? 0.33 ppm per day is not likely to be from your small water changes, however.

 

[rock_lobster]

Ever check your new salt water at the salinity you use? 0.33 ppm per day is not likely to be from your small water changes, however.

I havent tested the salt I use but It is really a minimal amount. My tank is only 20g but loaded with SPS. I dont actually even make water for changes. I just test salinity once a month and if it is a little low from sharing frags then I will add a tablespoon of dry salt right into the rear compartment. I do that no more than once a month sometimes Ill go several months with added adding any salt. I use reefcrystals.

 

[rock_lobster]

I havent tested the salt I use but It is really a minimal amount. My tank is only 20g but loaded with SPS. I dont actually even make water for changes. I just test salinity once a month and if it is a little low from sharing frags then I will add a tablespoon of dry salt right into the rear compartment. I do that no more than once a month sometimes Ill go several months with added adding any salt. I use reefcrystals.

I dose a lot of soda ash, calcium and magnesium so that probably keeps the salinity up for the most part to counter the fragging.

 

[rkpetersen]

It is remarkable that Brightwell makes so many similar mistakes.

The extensive mind-numbing run-on verbiage on the sides of their bottles indeed actually says very little and is often inaccurate. Also, their dosing recommendations can easily lead to overdosage, in my opinion and experience.

BTW, I still have unexplained elevated potassium in my tank, well over 500. I still think the source is Reef Fusion 2, after testing everything else, but I haven't bothered to switch to a different 2 part yet. Maybe OP and I should exchange some water. ;Shifty

 

[rock_lobster]

The extensive mind-numbing run-on verbiage on the sides of their bottles indeed actually says very little and is often inaccurate. Also, their dosing recommendations can easily lead to overdosage, in my opinion and experience.

BTW, I still have completely unexplained elevated potassium in my tank, well over 500. I've pretty much given up trying to figure out the source, after testing everything. Maybe OP and I should exchange some water. ;Shifty

HAHA that would be perfect! well it must be the food that you are using in your case if the salt checks out.

 

[rock_lobster]

I am just going to start adding the KCl directly to my dosing regimen 3ml week should be perfect. Funny how I bought spectracide to dose nitrates but then moved to NaNO3 to avoid messing with potassium. Now it actually looks like it might be perfect for my tank.

 

[Randy Holmes-Farley Verified Community Expert]

I dose a lot of soda ash, calcium and magnesium so that probably keeps the salinity up for the most part to counter the fragging.

Now that you remind me, that process alone reduces potassium, since those additions boost salinity, and correcting it back to normal over time reduces everything else, including potassium.

Adding 1.1 dkh per day will raise salinity about 32% per year and hence will reduce potassium by about 0.088% per day, or 0.35 ppm per day.