Hello all: I have an established heavily planted tank; the plants are
growing well, the fish are healthy, algae is minimal and everything looks
good. The tank is C02 injected, about 3 watts/gallon of light, and I add a
little Potassium Nitrate weekly to keep the nitrate levels up to where they
are (barely) detectable with a Hagen nitrate test kit. I do a 30% water
change weekly.

My only complaint is that I have found I have to test for and add Iron to
the water column daily. If I do not keep the iron at detectable levels I
will get really nasty hair algae (and lots of it) very quickly. For
example: I was out of town for only three days last month and when I
returned the tank was a big mess due to an explosion of hair algae.

I use Flourish twice a week, and Flourish Iron daily. I have about 50%
Flourite in my substrate, so there is iron there, but to prevent the algae
the iron has to actually be in the water column. I have been dosing the
Flourish Iron every morning so that the iron level in the tank is about .25
mg/l. By the next morning it is 0 and I have to dose again.

The daily testing and addition of Iron is getting to be a pain. I have
several questions:

1) Has anyone dosed iron levels to higher than about .25 mg/l ? I hesitate
to try this thinking it could be harmful to the fish. On the other hand
perhaps a higher dose of iron would last longer. I would really like to only
have to dose the iron once or twice a week, but even if I could just get it
to every second day it would be better.

2) Is there any product or chemical that will "time release" the iron into
the water column? (I have tried fertilizer tabs and they do not do the trick
as the iron stays in the substrate)

3) Does anybody think the iron in the water column might actually be
inhibiting the growth of the algae? Based on the observations in my tank, I
think this is what is going on, although I am aware that the conventional
wisdom is that the plants are out competing the algae when there are enough
of all the nutrients. My plants are getting plenty of iron from the
substrate though, and keep on growing like weeds even when the algae takes
off because there is no iron in the water column.

Any help/comments appreciated.

Thanks !!

You might try this:
Add about 5mls per 20 gal of tank of the Flourish.

Do this 3x a week

That's all you need to do for your set up.
Do 50% weekly water changes, add the K2SO4 after the water change and
add the KNO3, KH2PO4 + the traces 3x a week.

It's not the iron that's the issue, it's good plant growth.
I've had 1-2ppm iron levels but they never last long.

You gain nothing by dosing daily vs 3x a week.
I dose on the water change day and then 2 times more.
Your plants don't need any more.
Regards,
Tom Barr