As some of you may remember, I have been having a heck of a time keeping
trace elements in my show tank. As a result of these problems I have been
doing some tests on existing fertilizers to see how much it takes to get
a measurable level with my iron test kit. Here is the data that I have
collected so far.
Horizon Growers, 2 teaspons/55gal every other week
Tetra FloraPride (iron-intensive), 10ml/10gal & 10ml/20gal @ water change
Duplaplant-24, 1 drop/50l
Ferrovit, 2.5ml/38gal every 14 days
Test Kit: Red Sea iron test kit
All test were done with 1 liter of distilled water.
Fertilizer # Drops to get ~0.1ppm iron
Horizon 8 drops
Tetra 12 drops
Ferrovit 20 drops
Dupla 4 drops
* Note: The dropper I used took 120 drops to get 10ml.
1. Seems to take A LOT more drops to get an iron reading then
I would have expected.
* I don't know how to read a test kit (could be)
* My test kit is wrong (maybe)
* These fertilizers really don't add much iron
2. It would really be nice to have someone run a similar test
on at least dupla with a different test kit to see if the
results are consistent.
3. Dupla costs big $$$, but even by this crude test it is at least
twice as concentrated as the closest competitor.
4. I dumped an entire 250ml bottle of ferrovit into my 180gal that
I have been having problems with and hardly got a trace of iron
to show up. I wouldn't waste the money.
5. To get a consistent iron reading on my 180 show tank that I have
been having problems with I used 2 bottles of Tetra (~$3.25ea) to
get a readign of ~0.1ppm.
6. I didn't test the dupla tabs only the dupla drops alone. It could
very well be that the tabs add a lot more iron.
Since several people recommended testing the test kit with distilled water,
I decided to take up the challenge. Unfortunately, it is not at all clear
what you should get for a reading. The recommended dosage doesn't even
register (or was not possible with only 1 liter of water). If anyone has
thoughts (especially hard data) on what we should expect in such a test
I would welcome the information.
Just thought that I would pass my test data along.