Laith

I am currently (using a dosing pump) dosing about 7ml of Flourish a day into a 200l tank, or almost 50ml a week.

After a couple of weeks of the above, I notice a slight yellowish tinge on some of the plants so I do the following:

1. Test my JBL Fe test kit by mixing 1ml of Flourish in 100ml of RO water, then using 1.25ml of this mix in 200ml of RO water. The test kit gives me the expected result of 0.2mg/l of Fe.

2. Immediately after this I test the water in the 200l planted tank. Fe shows 0...

I know, Fe test kits are notoriously bad but remember that I just tested the kit against a known concentration and it matched. The Flourish bottle used for the test is the same as that currently being using for dosing the tank.

Several possibilities here:

1. My tank is going through Fe at the rate of 50ml of Flourish a week.

2. The Fe in the Flourish is precipitating out in the tank for some reason (?).

3. My highish KH of 13 is having a direct impact on the Fe somehow...

Tank is 3wpg, pressurized CO2 to around 40mg/l, lots of the other nutrients dosing through a second dosing pump (KNO3, K2SO4 and KH2PO4). I'm also dosing Flourish Excel at the Seachem recommended dosages to see if it has any positive impact on a CO2 injected tank (aside from as a possible algaecide).

Suggestions or comments? Anyone else getting such high Fe uptake levels? I guess I could just increase the Flourish dosing to 10 or 12 ml a day and see what the results are...

dennis

Well, in high light, high growth tanks Flourish is often dosed at 2-3ml per 10 gallons(38l), 3x week.....or up to 9ml/p 10 gallons a week. A formula I used in my tanks is 1ml per gallon(3.8l) per week. I did not notice any issues, either deficicency or excess, when doing this. (side not, since switching from flourish to CSM+B I have not had the same terrififc results in my tanks)

If one compares this to your tank(200l=52gallons), you are dosing 1ml per 10 gallons(38 liters) per week. This is 10% of what I have found to work well.

How much Fe, in ppm, do you add with the 50ml of Flourish. Sorry, I don't know the concentration of Fe in it so I can't do the math.

On the other hand, it would seem that 50ml of flourish/week would be enough. I think the most important question is how are your plants growing?

As far as precipitation of Fe goes, does the PO4 and Fe get dosed within .5 hours of each other? I don't know about high kH affecting Fe, soory, no idea. I thought Excel was supposed to make Fe more available.

Cavan Allen

I think that option 1 is the most likely. If you've really got things going, you will indeed go through a whole lot of iron.

My 44 gallon (167 litre) tank goes through a lot. I add 8mls of Flourish and 12-14mls of Flourish Iron every day. My KH is 4, but I don't think that has much if anything to do with it.

I don't bother with iron test kits. The plants are a much better indicator of sufficient iron levels. If it looks like they need more, add it, even of you can't believe how much you're dumping in.

Do you add a separate source of just iron? I'd do that on top of the Flourish.

Laith

I have found similar results moving from CSM+B to Flourish. Flourish has given me much better results than CSM+B...

No, I'm dosing 50ml of Flourish per week. Works out to over 5ml per 10 gallons per week (at 200l but I usually calculate based on 175l volume).

Works out to 0.91mg/l of Fe a week (per the Fertilator and using 175l as actual volume).

There is a 2 hour period between the dosing of the Flourish and the dosing of the macros.

Thanks for the answers. So 50ml a week doesn't sound extreme anymore . I guess I should just go ahead and increase the dosing. I have a bottle of Flourish Fe around but have always thought that if the plants need more Fe they probably also need more traces so I might as well just add more Flourish...

Cavan Allen

That's what I used to think, but that isn't always the case (it might be ok on a low light tank). Adding more Flourish Iron than Flourish has worked well for me.

You will undoubtedly see an increase in leaf size, color, and overall vigor.

Laith

Ok, I'll give that a try.

I'll keep the Flourish dosing at 7ml a day but add 5ml a day of Flourish Fe to the dosing pump recipient and see what the results are. That should give me about about 0.42mg/l of Fe per day into the tank compared to the 0.13mg/l per day I've been adding up until now.

Mnemia

I'm just a beginner (only been at this a year), but I couldn't believe how much healthier my plants started to look when I began dosing Flourish and Flourish Iron at extremely high rates. Especially my Echinodorus species have much bigger leaves that are a deeper green color now. I now dose Flourish Iron daily at 3 mL for 20 gallons, and things look way better than they ever have before. Lack of iron seems to have been the final missing element for my tanks.

dennis

Laith,

Sorry to have said that in a funny way but I agree, I like Flourish over CSM. Much better results with Flourish. Also, my math was a bit off, but I am dosing 2x what you are. 1ml p/gal week versus your 1ml per/2 gal a week. The 2 hour window between macro and micro dosing should, from what I have read, be enough to avoid any PO4/Fe binding issues.

I believe Fe is one of the most important of the traces, aside from Mg and Ca. It is usually more limitited than Mg/Ca. Thus, it is logical to me that one might not be deficient in other traces while actually deficicent in Fe.

None of this answers your original question though...."After a couple of weeks of the above, I notice a slight yellowish tinge on some of the plants so I do the following"

Is it percipitate, algae, or what?

niko

This topic needs to be kept up because I have the feeling that many people underdose the iron.

Testing is not the best approach to determine if one adds enough iron. It's best to observe certain plants that quickly (within a day) get pale if iron is lacking. For example Mayaca or Eichornia diversifolia (stargrass).

My experience with testing for iron is similar to Laith's. I added certain amount of Fluorish Iron to a 1 gallon jug and tested the Iron content. I added more and kept testing until I read a definite 0.1 ppm.

Then I added the corresponding amount in a 55 gal. tank. Tested almost immediately. Got no reading. Added more Fluorish Iron - no reading. I added at least 3 or 4 times (if not more I don't remember well) the amount needed and never got a reading. Since then I don't test for iron.

A short time ago I had a tank full of E. diversifolia that would turn pale within a day and a half if I didn't add enough iron. And here's the interesting part: I was adding 4 ml. of CSM+B and Sequestrene 330 solution (a 10% Iron chelate) daily to a 18 gal. tank. The Iron concentration in that combined solution was much more than the Iron concentration in Fluorish Iron.

I don't think that my solution was bad. I prepared it once a week so it was fresh, the bottle is white, not transparent. 23.81 grams of CSM+B and 23.81 grams of Sequestrene in 500 ml. of RO water. Four mls. of that killer mix is a lot of Iron. But the plants did need it.

The moral of my rant is that more Iron seems to be not only good but probably much needed.

--Nikolay

Laith

I've just mixed up a new batch of micros for the dosing reservoir.

A mixture of Flourish and Flourish Fe that'll give me 0.15mg/l Fe a day from the Flourish and 0.15mg/l of Fe from the Flourish Fe. Total of 0.3mg/l of Fe a day. (All this according to the Fertilator...).

I was going to make it stronger but this is already double what I was dosing before so I'll take it a step at a time.