is it safe to say that the addition of extra iron in a tank will bring out more red coloration in plants? or am i wrong?

Well, I know that persons (ahem...Tim) who are really good at growing red plants would be the best to answer. Yet, I'll throw in a few comments to "get the ball rolling". I personally really, really love burgundy and reds in my terrestrial gardening. I have a particularly bad case of "RED-Envy". So, while I'm not greatly successful, I do pay attention to this topic. And this topic tends to be brought up regularly on most aquatic plant forums.


First, you need to be growing a species of plant which has a good ability to express reds. Although, duh, this would be a given. However, some plants show reds well in most environments and growing conditions. Even in low tech and low light tanks. Other plants will never develop reds until you give them a high tech environment. And some plants not until that high tech is running at a top notch rate. Meaning, maximum injected CO2 gas.

Once given a good growing environment, light wise & CO2; then bumping up iron dosing can help. Depending again, on which plants you have. But as was discussed at our last meeting, it is vital to give any plants enough time to show the results. Bump dosing up slowly. Maintain that regime for at least two weeks. Then if things looked good and were showing better reds, perhaps bump up a slight bit more to really tweak it. Once an increase showed no significant improvement, then drop amounts back down to the previous level. IE., if you dose 5ml of iron per dose. Go to 6ml, try for two weeks. Then try 7 ml per dose.

Now, here's the trickier part. I've run medium and high light levels, and with lots of iron. Efren tested my water and my iron was high. However I never managed to get Ludwigia repens 'Rubin' to be the blood red color that Tim's would be. (RED-Envy!!.) It took me several years before I came to conclude that the problem was not my nutrient dosing; more my CO2 injection. I injected pressurized CO2 gas - everyday, just not enough, not maximized. After having several episodes of fish gasping at the water's surface I can be a scardy-cat about the CO2. Granted, some of this is my inexperience, some can be the particular fish load, and some is just wonky equipment. I've noticed some species of fish handle CO2 better, and others start to gasp sooner. The larger ($10.00 each) Rainbows in my tank didn't like it, and after two gasping episodes they were eventually relocated. When I lost SAEs in another bad gasping episode, my Rummy-nose tetras were swimming around .. no problemo. It could be how they breath; or where they come from originally, IE., deep black-water conditions vs. fast flowing rivers; or even body mass. Also, good CO2 equipment helps. My needle valve is a P.O.S.! Just a teeny-tiny bump sends my rate from OKay to rotten. This complicated matters for me.

Any woo . . . just waxing on and on to say, sometimes a little more iron helps. Sometimes there is a whole lot of other tweaking to be done.

wow thanks kate! ive got 78 watts of t-5 ho lighting on my 46 gallon. im not currently injecting co2. i am however dosing exel. the ''red'' plants that i am growing are bold hygro, blyxa japonica, and Myriophyllum heterophyllum.

Kate sums it up pretty well....it's a 'mulitiple factors' type of answer.

a couple of things to try:

- let some of the plants reach the top of the tank. If the reds start 'popping' near the tops of the plants, you probably have a light deficiency to some degree limiting you in that tank. Before you get more light though, review what you want from the tank - easy maintenance?....it's probably not worth the effort trying to bump up the lighting (requiring CO2 injection, and more fertilization).

- if the plants still don't get too red at the top, you can look into bumping up the excel dosing by 50% and the iron dosing by 20% for a few weeks to see what happens.

- I can't remember if this tank is a soil tank or not.....if it is, dose very little iron at first, a lot of times doing any dosing (other than excel) in a soil tank leads to algae problems.....


my final two cents - a lot of times it takes a high-tech tank running smoothly to get the 'super reds' out. This can be a Pandora's box trying to achieve this, you need to be very deligent in the dosing and CO2 to get to that point, and can easily run into CO2 toxicity, imbalance leading to algae problems, and overall frustration trying to achieve it.