YES,Carbon WILL remove iron from your aquarium.

[Stan510]

Live and learn. I just started to use carbon in my aquarium filter and also kept up adding Seachem Iron. Despite the carbon being in the aquarium a good three weeks already? I one day looked at the nylon sock the carbon was in and it was all a RUST color- So,no doubt Seachem iron is concentrated and no doubt that carbon can still be removing what you are putting faster than you can add even weeks old carbon.
So now,I expect to get even longer use out the carbon..as used between dosings.

 

[StevenF]

Note quite. Seachem iron is iron gluconaate. Gluconate is a type of acidic sugar. bacteria consume gluconate very quickly (Bacteria are pressent in your filter).. When the gluconate is gone the iron rusts. Some peaple have to add iron gluconate almost daily to maintain soluble iron levels adequate for plant growth. Iron oxide is not soluble and not useable by plants.

I use iron DTPA in my aquarium bacteria won't consume it and it will last a long time as long as the PH is below 7.5 (but may be stable up to a PH of 8). I dose once a week to to maintain a level of 0.1ppm in the aquarium. DTPA is safe for shrimp and fish..

Take a container with 100nl of distilled water and one milliliter of vinegar and 3.44 grams of iron gluconate (equvelent to 1/2TSP+1/4tsp+1/8tsp) or iron DTPA. one one milileater dose will achieve 0.1ppm of iron in a 10 gallon tank about 40 liters) after your weekly water change.

Note this recipe can be adjusted using:

Rotala Butterfly | Planted Aquarium Nutrient Dosing Calculator

Planted Aquarium Nutrient Dosing Calculator

rotalabutterfly.com

Sources of iron DTPA
s/www.nilocg.com/shop/iron-chelate-11-dtpa-for-aquarium-plants/

DTPA Chelated Iron (Fe 11%) Aquarium Fertilizer - 0.5lb Jar

Shop DTPA Chelated Iron (Fe 11%) Aquarium Fertilizer (0.5lb Jar) for your planted aquarium aquascape. Brand: Green Leaf Aquariums (GLA). Orders ship fast worldwide and get free shipping on orders $125.

greenleafaquariums.com

 

[Stan510]

I hear you. I notice it does take a lot of Seachem iron to feed the plants in the 240 gallon and it amazes me how that amount is so much more ,100x more-than I have used on land plants- garden plants. I even wondered a few times where those plants get that iron in nature? How many streams or paddys have iron rich water?
The last time I was at Home Depot,I looked to see if they sold iron. I was surprised to see one small bottle of liquid iron and it was more than Seachem.
Also,so many of those advertisements to order a pound of iron for cheap? Turns out they are "out of stock"..hmm.

 

[Stan510]

Also..my aquarium set up with plants is going on 4 years old in May. As an oldtimer? It is very surprising how much fertilizing it takes really to get that dark green fast growth. Much more than normal potted garden plants and much,much more than houseplants. I could get by on fish poop alone. I've done that. A few plants thrived on that...more though sort of sat or new growth was very small.
This month I "went for it" and added more iron,more potassium, and finally even added a mild land fertilizer of 6-12-6. For just a couple of weeks,I see better color coming over the plants.
The fish seem fine. Eat like Piranhas all the food I put in.
Did I say Putin? dang me!

 

[Stan510]

Thanks..that IS in stock. 1/2 pound for $10 is a deal.
One more question. How about iron pills sold at health stores? What kind of iron is that and is it useable in aquariums?

 

[StevenF]

Stan510​

One more question. How about iron pills sold at health stores? What kind of iron is that and is it useable in aquariums?

mainly iron sulfate and iron gluconate. but there could be others. If you have any KH in your tank iron sulfate would react with the KH and converting to iron oxide very quickly.

Other than iron DTPA the only practical iron fertilizer is Iron EDDHA It is stable up to a PH of about 12. But it tints the water red. Some people use it but most don't like the color. If you are interested you could try this DTPA micro fertilizer DTPA micro fertilizer. This is a micro fertilizer with iron DTPA plus all the other micros It is much better balanced than most others on the market. Most micro fertilizer on the market are typically deficient in zinc and copper. I have read that a zinc deficiency can result in smaller leaves If you use this micro you would only have to dose nitrate, potassium, Calcium, Magneisum, phosphate, Sulfur and chloride. Fish waist might b all you ned for Nitrogen potassium, and phosphate. And your tap water might have enough calcium and magnesium or sulfate and chloride.

My tank is an uses RO water and hasan inert substrate. Most of the time my plants would grow. I eventually concluded mosts commercial fertilizer would not work in my tank and I made my own micro fertilizer. My fist attempt worked better than any commercial fertilizer I tried. The fertilizer recipe I am using now is similar to the GLA iron fertilizer I listed above.

 

[Stan510]

I've found myself saying that iron and potassium are the only ferts I've tried that I could see the difference and just the other day Dr. Kevin Nomak said the same thing..he only has iron and potassium that he doses everyday by hand. Whatever amount he didn't say.
THANKS.