Backyard Aquaponics
A place to discuss aquaponics

Sorry Sammy, but you're wrong. There's hardly any potassium in commercial fish feeds because fish do not need potassium to live/grow, not because it would cause them heart problems.

Otherwise all of my fish would have had heart attacks long ago, since they're swimming in a sea of 50-100ppm potassium.

Wood ash, kelp meal, and worm tea are all good sources. Also potassium hydroxide if your PH is low. I would be worried that too small of chunks would get washed through the GB and end up in the ST or FT. All goes to the same spot hopefully- your roots. But it seems like placing it directly by the effected plant would be best. In the case of a GB plant.

I mean % of potassium in their feed, not the water.
I heard it from a rather reputable source, but unfortunately I do not have documents to support it.
Do you supplement K in your system at all?

I most certainly do supplement K. Mono-Potassium Phosphate, Potassium Nitrate, Potassium BiCarbonate, and Potassium Silicate. I also have Potassium Hydroxide, but haven't used it.

Most vermiculture sites I have seen recommend liquidizing aka blending, the waste veg etc BEFORE putting into the worm bed SO . . . putting mush into the GB will probably encourage the worms to digest it quicker, enhancing the GB and not allowing the ants etc to colonise.

Do you have a 'place' for the worms in the GB? Once again, previous APer's have a place for worm colonies in the GB.

And the worms don't drown on F&D!!

My system is a Flood and Drain. I just put about a dozen worms randomly around the grow bed. Figured that was the way to go. Have been digging through the clay balls recently, but not seen any worms, so presume they became ant food.

And most of us must supplement K in this fashion due to low K values in the fish feed- which are low (from what I've been told) because high levels of K in the fish feed have a detrimental effect on the fishes cardiovascular system.

So does it jeopardize are fish if we supplement K? I'd hate to have a massive cardiac arrest of my tilapia?

Not that I know of. I can't recall who specifically, but one of the speakers at the aquatic eco AP workshop (Lennard, Rakocy, aquatic eco staff) mentioned excess K in fish feed being harmful to the cardiovascular health of fish. Totally different than ppm of ionized K in your system water.

Did you know that fish can absorb phosphates from the water to use in addition to what they eat? It would stand to reason that K would be the same way.

And now people are worried about potassium in their system, because of what a "fish store employee" told you.

Not sure how you got fish store employee out of me saying Rakocy, Lennard, or one of the Aquatic Eco staff members. I believe most would consider them rather reputable.

Didn't mean to mislead anyone or rustle your jimmies so sorry for that.

Not sure how you got fish store employee out of me saying Rakocy, Lennard, or one of the Aquatic Eco staff members. I believe most would consider them rather reputable.

Didn't mean to mislead anyone or rustle your jimmies so sorry for that.

I want to go to your "fish store" Sam.lol I would say the are reputable in this field. Kind of like saying Einstein knew a bit about physics.

I could have sworn this was the same thread that was talking about banana peels a week ago:
viewtopic.php?f=1&t=22848&

I think the general consensis was that there wasn't enough potassium in banana peels to make much of a difference. Jay worked out that 1 tomato plant would require 78 bananas.

See where the thread goes...you never know??? I solved the problem by eliminated my media and replacing with banana peels.