Low Potassium due to Macro Algae Uptake?

[cbleehk]

Hi,

I've been consistently tested low on K at around 325. I've been dosing K at around 2.2ppm per day (calculated according to redsea Potassium+ bottle).

My tank is 4 months old and i have a bunch of SPS & LPS in the tank. Some easier SPS like Seria & Stylo seem to be doing fine growing slowly.

My macro algae Chaeto had been growing very fast. I need to harvest every month and I have a thin layer of green/dark brown algae on my rocks.

I find that water changes don't move the value much (have doing 25% changes with ReaSea coral pro salt). I've tested with 2 different test kits.

My question is, should I try to dose more K to catch up? According to red sea, it's about 250ml to catch up and I can do it with a doser over a week. Is it worth it?

Could it be my chaeto eating my my K? I'm running 12hr reverse daylight on the algae turf LED. Should I reduce it?

I also have undetectable PO4 (using Salifert), and yet I have small patches of cyno and crazy chaeto growth. Should I get another test kit to validate it?

My Xenia has been growing like weed, could this be an indicator my water has high nutrients?

I'm still trying to learn how much dosing of everything I need to do. Wondering if there's any pointers as to where to start? I'm currently dosing KZ Sponge power, KZ Coral Vitalizer, AF Power food, AF Growth boost all at 1/3 of the instructions daily. Also dosing all red sea color program ABCD, Ca, Mg, and randy's alk mix.

Thanks!

 

[LouieP]

Yes I would increase your potassium dosages so that you bring it up over a few days and test about 1 hour after each dose

 

[Randy Holmes-Farley Verified Community Expert]

I would maintain normal potassium values. All organisms contain it, as do all foods. So it may not deplete in all tanks (it did not in mine), but depending on the foods used and other factors, it may deplete.

 

[cbleehk]

Guess what... only a true noob like myself who cannot read instructions would make this mistake...

Apparently both the test kits ask you to use "the amount dropped from titration" to map the ppm on the chart. And because it only took 0.1m on my Colombo test kit and they had a formula to calculate in case the amount dropped is not on the chart, I found out that I've calculated it inversely. I've done so many Ca, Mg, & KH tests that I completely overlooked this.

This means I've got around 475ppm of potassium in my water. I'm glad I am no on tract to be in range for K!

Thanks guys, case closed!