Eco Rose - How much to apply?

[Castaway]

I managed to get some Eco Rose (potassium bicarbonate) yesterday. How many teaspoons would you add to a Grow Bed? I put in half a teaspoon of the stuff directly into the auto-siphon of each growbed yesterday but am unsure if its enough? I don't want to overdo it and risk poisoning the fish.

Would Potash do the same thing?

[Murray]

HI Castaway,
That is about right I would think. That is about what I do here on my systems. I also spray it as a foliant spray to help control mildew especially on cucumbers. I suspect the a little of the material is absorbed during this process.

Have not added potash of another kind so I do not know if it has any ill effects on the fish.
ECO ROSE is Potassium Bicarbonate.
The recommended element is Potassium Carbonate but not being a chemist I really do not know if there is a difference between Carbonate and Bicarbonate.

The thing is that "Eco Rose" is easily obtained and appears to do the job well.

[aussieap]

Do a pH test. Add a little if you are under 7. Test again next day. Use it to buffer to 7-7.5pH. A proper functioning system will drift lower pH wise and eco rose or other organic potassium products, should be a part of our day to day ap tools.

Calcium is the other nutrient that tends to be deficient in ap systems. Calcium carbonate can be added alternately with the eco rose so both are in the system and ur pH remains within desired levels. Just add it in the sump or via the growbeds, it can burn fish gills if added directly to the fish tank.

[Castaway]

Thanks Darren - I noticed the pH in my system is fairly stable at around 7.2 with or without Eco Rose but hopefully it will add to the health of some of the plants that look a little stressed and withered. We have a lot of plants in the Maximus system so they are sucking in a lot of nutrients from a small fish mass so I guess any lack of potassium or trace elements in the system is made apparent very quickly in plant stress. I didn't know you could use Eco Rose as a buffer though.

Thanks for the tip re: Calcium Carbonate. Rather than add Calcium Carbonate in the form of a powder - we have a little bag of seashells buried in one of the Grow Beds. (A little tip from Murray) who says it will keep the pH fairly stable and shouldn't hurt the fish. Maybe that's enough to keep the plants happy too.