Backyard Aquaponics
A place to discuss aquaponics

EDTA Iron is not they type of chelated iron you want, it may actually be bad for plants.

EDDHA and DTPA are what you are looking for I believe.

As to the web address for the Sprint 330, Uh, I usually stop in at BWI in Apopka FL and pick it up. I don't know if you can even search for it on their web site without an account.
Oh, I guess you can search for it
http://www.bwicompanies.com/search.aspx?val=sprint%20330
Though that probably won't help you get any since they are a wholesale company and probably won't ship unless you put in a $5000 order.

You can probably search amazon or e-bay for SPRINT® 330

Or pm me if you are only interested in 1 lb of it here in FL.

I place a rusty bolt or old hand tool in my grow bed. Never have problems with Iron.

someone told me to this but how safe is doing that?

Well if the rusty bit is just Iron then it is probably not dangerous though it may do little to actually help the Iron situation.

However, most metals (especially hardware) is rarely pure Iron and other metals can leach and be dangerous to fish. Like Zinc from galvanized metals can be especially bad for fish as the pH drops. Copper and Nickel can also be bad for fish.

With media beds, I've found that an occasional dose of chelated iron until the system settles in and then once the pH is down between 6.5-7 the Iron only rarely needs to be added. In other types of systems like rafts and towers and commercial scale systems, Iron seems to be needed more often. I think perhaps some Iron is available from my gravel.

I am removig rust from cast iron cookware with electrolysis. I am mixing 1 table spon baking soda to one gallon water and using a 12 volt battery charger. When you dump mixture on my lawn it becomes very dark green . I think this due to the high iron, as the fluid is very orange almost red. I would like to mix maby one gallon at a time to a 1500 gallon system. My ph stays around 7.4 to 7.6. What do you think. Jerry

Jerry,
would that electrolysis work with potassium bicarbonate instead of the baking soda (sodium bicarbonate)?
That would maybe give you potassium and iron in the mixture rather than the sodium?