Using potash as potassium source

[isu712]

I have an idea and was wondering if anyone out there might have already tried it. I know that some people will use Muriate of Potash as a K source in gardening. Would it work to add some of it in a media filter bag and place it in the filter to slowly dissolve? Or will it dissolve too quickly? I have done the same thing with crushed coral to raise the KH and calcium level in my NPT. Also, I know that plants need a fair amount of K, but can you overdose a tank with K?

Anyway, I was just wondering if anyone has thought about this or if I'm completely nuts.

[AaronT]

I use it underneath my soil substrate tanks when I set them up initially. It works well for the first couple of months.

[isu712]

Do you think that it simply gets used up or something else happens?

[Spiritwind]

People use Potassium Chloride to provide Potassium in aquariums. How it dissolves may depend on its purity. I would not add a pound block of it into a filter and hope to let it leech into the water column. It is used as a table salt substitute, personally never used but I imagine it also acts like table salt in water. Be wary about what impurities there are in your garden Potash, might be harmful things in there. There probably are different grades of it, like garden, food, pharmaceutical. Probably is a limit to the K for safety but you are also putting in Cl into the water. If the stuff you have is pure enough then you can use it for dosing, but not that style of coral buffering you have done in the past.

[AaronT]

I think it just gets used up.