This is part of a series on Aquaponic Water Testing.
Iron is one of the most common deficiencies in Aquaponics systems. The main symptom of a deficiency is interveinal chlorosis on the newest leaves of the plant. Many other deficiencies cause interveinal chlorosis, so relying on visual identification can be hard, especially for inexperienced growers.
Aquarium test kits, like the Seachem MultiTest Iron, should be avoided if possible. They lack the ability to accurately check for chelated iron. However, they will answer the question “Is there Iron?”
I own and use the Hanna Checker HI721.
If you use Fe-EDDHA, or Fe-HBED in your system, beware test interference. The YSI MR test is the most accurate test I’ve found. It separates out the Iron Reducer and the phenanthroline reagent, allowing for the photometer to be zeroed in between the two steps.
- Seachem MultiTest Iron
$13.09 / 75 = $0.17ea
- Hanna Checker HI721 (0.00 – 5.00; MDL 0.01; Resolution 0.01)
$49.13@Amazon Meter + 6 tests.
$6/25 refills=$0.24 ea
- LaMotte Smart3 + 4315-H (0.0-10.0, MDL 0.05)
$37 / 100 = $0.37ea
- Hach DR900 + 8008 (0.02 – 3.0; Resolution = 0.021)
$21.95@Hach / 100 = $0.22ea
- YSI 9500 + Iron MR (0 – 5.0; MDL 0.02)
$46 / 50 = $0.92ea OR $104.40 / 250 = $0.42ea
- YSI 9500 + Iron HR (0-10.0; MDL 0.05)
$23.49 / 50 = $0.47ea OR $46.98 / 250 = $0.19ea
Have I missed an Iron test that would work for Aquaponics? Let me know in the comments and I’ll update this page.