Chelated Iron

 Update:

I think I have found a good source of chelated iron.
CLICK HERE

A product called Ironite also looks good.  CLICK HERE for the whole story about lead and arsenic levels found in that product


TCLynx wrote this comment about  Maxicrop

 " As Nate noted, fish emulsion can provide the ammonia source for initial cycling but one must be careful and it might not be the best choice for cycling for all situations. I would definitely not recommend using fish emulsion in any system with fish already in it unless you are an expert. It could spike the ammonia too high and kill off fish if one was not very careful how they went about it. For fishless pre-cycling it might be ok.

For those having issues with plants not flowering or setting fruit well, potassium deficiency can cause that and maxicrop original might be a good supplement to help improve things on that front.

As to people saying to dose with maxicrop to keep the plants going till the nitrates come online, well I'm not sure that is really an accurate comment as to what the maxicrop actually provides for the plants. However, in a new system, nitrate is not the only thing the plants are waiting for so giving a dose of seaweed extract can help your plants get a good start with trace nutrients and many of the complex substances that won't be available in a fresh gravel bed. (I also think some worm castings can provide much benefit for a new system too.)"

RupertofOz wrote this about letting the system mature 
Just feed your fish a quality aquaculture pellet feed... they contain all the essentially trace elements necessary for plant growth in an aquaponics system.. and the ammonia wastes from the fish... provide all the necessary "nitrates" required for abundant growth...

"It's that simple.... and safe...
Other additives are only utilized if deficiencies show... usually due to pH associated "lockouts"...
Cycling a system only requires a pure ammonia source.. and only takes a few weeks..."

Original Post:
I got the idea add iron chelate to prevent chlorosis from Murray Hallam's video.  The main symptom of iron deficiency is yellowing leaves, especially the youngest leaves. The veins of the leaf usually remain green.  So I went out to buy some today, and found it difficult to get straight iron chelate.

Then I came up with this half baked idea to use dried sea weed since it has no nitrates and lots of iron.   I fed a pinch to my fish and they gobbled it up; they really liked it! I thought I was on to something good.

Then I though better about it, and tested with a very small amount into a large tank of water.  I'm so glad I did not put more than that little pinch in the aquaponic system.  It turns the water dark as coffee
.  

Here's what Murray uses

A source CLICK HERE


Update June 15 2012
The topic of nutrients is quite a demanding study.   I have written several posts pertaining to nutrient uptake.   Nutrient Deficiencies