I can test for N and P, but what about potassium?

[Colin_BC]

I can test to see how my Nitrogen and Phosphate levels are in my planted tank so I know if anything needs to be added, but how do you know if your potassium levels are adequate? My algae problem has been tackled by adding Nitrogen to boost by Nitrates to 10 (thanks Bangin!). My phosphates are quite low (1-2) and my nitrates are around 10, but it has reached a point now where I haven't added Nitrogen in a bit and my phosphates are going down any more (not that I need them to now). Since it looks to me like consumption of N and P have come to a standstill, I'm thinking this means that potassium is now my limiting factor. Is that the only way to know if your ned potassium, or are there real ways to test for potassium levels?

Colin

 

[Bangin]

You'll notice a deficiency if older leaves turn yellow (and/or small holes), I believe.

You can test for potassium, but it's a very expensive test kit. Most people don't even bother with it. Here's a link that explains different fertilizers.

http/www.plantedtank.net/fertilizers.html

"Potassium can be added via potassium sulfate (K2SO4) or potassium chloride(No-Salt). The target range for potasium is 20 ppm. Potassium is difficult to test for and is not toxic to fish even at much higher dosages, so it is generally dosed at water change time to a sufficient level to bring the water change volume to that level. "

It all boils down to this....we never know the true levels of potassium!

 

[Colin_BC]

I have noticed some tiny holes with a brown edge on the leaves of a couple of my plants. I had thought before that was from algae. Today I saw some similar holes on week old growth of a fast growing plant (unsure of name at this point). I can pick up some Seachem Potassium today at the LFS. Would this suffice in place of the K2SO4? I'm going in anyways to see if he's brought in another killi for me. He got me a male killi and was holding it for me, but in between the time I called him and the time I made it to the store, it jumped out of the tank. He's also trying to get a pair of triple red cacatuoides for me

Colin

 

[Bangin]

My algae problem has been tackled by adding Nitrogen to boost by Nitrates to 10 (thanks Bangin!).

I forgot to say you're welcome! I remember the mess I had on my hands after my nitrates went to zero!

Seachem should work for you. Good luck with the killifish and apistos!