Rock wool okay ? using fish?

[Pine]

Hello I am currently building an aquaponics system
I was wondering if rock wool is okay to use to hold my seedlings while using fish. The rockwool will sit in my hydrotron grow bed and receive a rise and fall of water and nutrients from a fish tank through the use of a pump and bell siphon. Will the glass etc from the rockwool be detremental to the fish? or is it okay to use.

[urbanfarmer]

Rockwool is fine. Make sure to pre-soak in a 5 to 5.5 pH solution to remove the residual lime from the processing, then rinse with tap water. Good luck!

[Pine]

Ok thanks very much!

I have seeds in it now :s removing them to wash the rockwool would be cumbersome

My tank is cycling for a few weeks, would just washing the lime away into the system and lowering the pH of the system manually to a stable level be safice?

[urbanfarmer]

Yes. If your pH is high, leave it there until your system is cycling. This will speed up the process dramatically. Once the bacteria establish themselves, you can lower the pH to have a better balance for the plants, fish, and bacteria.