Backyard Aquaponics
A place to discuss aquaponics

Hey guys,
I'm pretty new here but i've finally got my system up and running. I've read all about supplementing chemicals (i.e chelated iron) but I can't seem to find any exact information on what to supplement for.

What should I supplement for? I.e potassium, calcium etc

How should i do this?

Thanks,
William/WillyP123

Do you have deficiencies?
I add dolomite lime occasionally and seasol.
Banana skins.
Fish food is meant to have all the goodies anyway.
Some people add potassium carbonate?

It is said that AP systems are typically low in potassium, calcium and iron as these very important nutrients are under represented or nonexistent in fish food. However, there does seem to be apparent differences between AP systems causing one to be deficient while another is fine.

I supplement potassium with potassium hydroxide and calcium with calcium hydroxide when I need to bump my PH up a bit. Mine trends low so this is a perfect opportunity to supplement. I usually do calcium twice as much as potassium because I have heard that the disparity with regard to calcium is greater than with potassium. I also keep a bag of shell grit in my sump to add a little PH buffer and calcium. I add a small amount of iron every month or so using a liquid chelated iron.

You may want to consider a foliar spray as well. I am just starting to experiment with foliar sprays myself. I will post the results once I get any...

Obviously, new systems are deficient in everything so I add maxicrop for the first few months to help get the plants going.

It is a new system, so it will be deficient - would you recomend banana skins for potassium? or use potassium hydroxide?

How much should i add? I have a 180L system

Cheers

seaweed extract is the go for new systems - i.e. seasol

If your PH is low you should alternate potassium hydroxide and calcium hydroxide. The problem is that new systems are almost always run a high PH until the biofilter really kicks in and then usually trend lower. Even then though your PH may remain too high to supplement this way. It really will depend on your particular conditions and this won't really be known until after the system has cycled.

1. Don't add anything except seasol/maxicrop while cycling unless things are REALLY out of whack with your PH. If that happens, post the issue here.

2. Once your system cycles if the PH runs low then it is recommended to alternate potassium hydroxide and calcium hydroxide to manage that. If it remains High after cycling you may have to get creative like adding banana peels.

As for the seasol/maxicrop I dont really measure mine very well... but here is what I was able to find for a specific measurement "250ml/1000L is added once at start up, then 30-45ml (2-3 capfuls) per 1000L weekly"

Hope this is helpful