Disappearing Fe/Iron absorption rate of plants?

[verkion]

Hello everyone,
I've been using EI for a little bit now and got around to dosing Fe on its own since I have a lot of "red" plants. So I added approximately 0.3ppm 2 days ago near lights out time, and remeasured the Fe level 5-6 hours after the lights came on yesterday and showed 0ppm of iron! I know I have a ridiculous amount of light going into my tank (about 10WPG homemade lights!!! i have to say its really cool to be able to visibly see plant growth after just an hour or two!), but can the plants really absorb that much in 12 hours or so? Is it just because they were "missing out" and they are absorbing more now?

I also have a UV filter going on that tank and I'm wondering if that is somehow affecting the Fe readings...

Thanks!!!
verkion

 

[jtparsons]

Hi Verkion,
This is my first post helping answer questions for people, usually Im the one asking the questions. Hope I can help out. Fe is really hard to quantify in aquariums. Most test kits except the very expensive ones dont work or are very inaccurate. Alot depends on the type of Fe your dosing gluconate fe (seachem) supposedly oxidizes faster than other types of fe, EDTA etc. Basically these different types of chelators make the iron available to plants for different amounts of time. These variables mixed with bad testing equipment will make it impossible to gauge your plants uptake ratio of Fe.

You could try to make reference solutions of Fe to ckeck the accuracy of your test kit. Im pretty sure these solutions would be time dependent also. Decreased readings over time.

All this being said EI is not about always knowing exactly what levels of all the fertz are in your water all the time. Dose a reccomended source of Fe on a schedule, watch plants carefully and you should be good.

How did you build your lights?

Not sure about the UV filter?

Im saving for a good way to test Fe right now. Im interested in a closer examination of Fe's role in the plant aqaurium. Big bucks! for real repeatable accuracy.

 

[SuperColey1]

As above poster says. Testing is a problem in planted tanks because then people go chasing problems that weren't there.

Dosing EI means you aren't too bothered what is in your tank at the moment. you know you dosed more than you needed and therefore you don't need to know if you have enough left in there. Then at the end of the week we do the heavy water change to remove some of the unused.

Saying that some poor quality chelators can get broken down in UV filters. Not overly knowledgable on this part so can't really advise on it. when I used to have a UV I was using TPN as trace and the chelator in that is apprently very good.

AC

 

[Tom Barr]

We can measure the Fe% in plant tissue based on different dosing routines. That's generally how fertilizers/routines are analyzed. Few do this in the hobby however

Regards,
Tom Barr

 

[verkion]

Hrm. I understand that the EI is a system where exact testing of the water is not needed. I also know that OTC test kits, (Hagen etc.) aren't the most accurate things in the world. However, I did figure I could use it as a "delta" measurement system, i.e. track the change in Iron, Nitrate, or Phosphorous.

In my case, with a Hagen Master Test kit, the chelated iron measurement went from deep "blue/purple" to completely clear in the course of 14 hours or so. I'm dosing using Tailored Aquatics' Amazon Iron which should raise Iron concentration by 0.1ppm per 50G of water. My tank is 27G so that should be 0.185ppm or so. I dumped in 2 capfuls which would give me roughly 0.35 to 0.40ppm...and it all disappeared overnight?

I guess my question is if there are nutrient deficiencies, that are corrected, will plants absorb a huge amount and then ramp back down? (Like a spike and then decay to steady-state?). And could my UV sterilizer be causing the chelated iron to breakdown/oxidize/disappear/not be in a measurable form using my test kits?

Thanks!

 

[evandro.carrenho]

Whenever I had UV turned on, I observed the same issue. Fe dissappears quickly. Without UV, Fe readings were detected even 2 days after dosing.

Regards,
Evandro.

 

[verkion]

Oh, I realized I never answered the lighting question... Yeah, I just built it from parts at Home Depot. 2xDual "screw base" lightbulb receptacles = 4x27W Screw in CF Daylights, 2x20W T12 (this set is due to get replaced one of these days...), and 2x65W Coralife fixture I disassembled to fit in my Canopy. There's a big 80mm fan in the back moving air, and I sit my wood canopy slightly forward to allow the air to circulate out.

Here's a pic of my artificial sun...

The camera dimmed everything down, but just use your imagination.

verkion

 

[Tom Barr]

I think I'd work on that DIY light and CO2 issues before even bothering to tweak Fe.


Fe is added to non limiting levels pretty much, this is easy to do.

It's chelated and stays in solution a longer time frame, based on KH and the Chelator itself's optima.

I do not think you will really gain that much from testing N, P or Fe.
I really did not, just did more work.

If I have a specific question, eg, what is the max uptake of NO3 over 1 week under very high light, non limiting nutrients and CO2, then, I do not mind and learn a lot more from testing because I'm going after a generalized, but specific question that can be applied broadly. It's just for a week and not some long term commitment.

If all I want to do is reset things and target a range, EI works perfect for that goal. Simple, easy and fast and quite accurate over the targeted ranges.



Regards,
Tom Barr

 

[verkion]

What? The DIY Lighting too ghetto? I'm bubbling 3-5 BPS CO2 through a powerhead at the moment, and my plants all seem to be enjoying the CO2 While I'm sure the light output would be as ideal as 4x65W Power Compacts, it is very, very bright in the tank...most would probably say too bright! 4 x 6500K, 27W CFL, a 6500 Coralife PCand 10K Coralife PC. The T12's in the back are slated for replacement soon enough...as soon as another good deal comes up on the 2x65W Coralife fixtures. Those bulbs are 5500K and a PlantGro spectrum bulb.

And yes, I have to admit the CO2 is DIY at the moment too, but I've got a method of using multiple CO2 reactors to provide a nice constant bubble rate of 3-5 bps. Everything grows like weeds in the tank...I just wanted a deeper red color out of the "red plants" in my tank.

Thanks!

 

[VaughnH]

Many fluorescent bulbs are a bit deficient in producing red light, and you can't see reds unless the light source has some red light to be reflected to your eyes. So, if you get a couple of bulbs in your mix that have good red peaks in their spectra you will get deeper red colors in your red plants and fish.

It is easy to state a solution like that, but the hard part is finding the appropriate bulbs. One very good one that you could use is a 55 watt GE9325K bulb. When I started using them I was astonished by how much better everything in the tank looked.

 

[Tom Barr]

What? The DIY Lighting too ghetto? I'm bubbling 3-5 BPS CO2 through a powerhead at the moment, and my plants all seem to be enjoying the CO2 While I'm sure the light output would be as ideal as 4x65W Power Compacts, it is very, very bright in the tank...most would probably say too bright! 4 x 6500K, 27W CFL, a 6500 Coralife PCand 10K Coralife PC. The T12's in the back are slated for replacement soon enough...as soon as another good deal comes up on the 2x65W Coralife fixtures. Those bulbs are 5500K and a PlantGro spectrum bulb.

And yes, I have to admit the CO2 is DIY at the moment too, but I've got a method of using multiple CO2 reactors to provide a nice constant bubble rate of 3-5 bps. Everything grows like weeds in the tank...I just wanted a deeper red color out of the "red plants" in my tank.

Thanks!

The Fe is not the way to get better reds.

GH and stable good CO2 will help a lot more.
Last I checked, there's no Fe in any red pigment in plants, it's just C, O, H.
Some enzymes use Fe, but this cane be said for many enzymes in plants for many other cofactor metals along various pathways that make pigments.

As long as you keep up on the CO2, you should be in good shape.

The light might be DIY, but you will get more results from upgrading that and CO2, than you ever will from playing with Fe and even less from testing it.

Fe is pretty far down the chain of importance, that's not to say it's not important, but it's relative.

the Ge bulb is pretty good and reasonable cost for the Red color you are after, a DIY 2x 55/65W linear 4 pin from A&H supply will certainly make things bright and for not much.

Then a decent CO2 gas tank set up, now you are in business.
No rush, but just live with it till you can work on those and do not spend too much time obsessing over smaller details with Fe.
It's really not that important nor fruitful.

This is an old old topic from way back. No one ever really found much relationship other than good/better general growth using Traces. Not color.

Old myths die hard.

Regards,
tom Barr




Regards,
Tom Barr

 

[verkion]

Ahhh...ok!!! Thanks for the input guys! I do appreciate it. BTW, I figured out why the iron was disappearing! It appears the culprit IS in fact the UV sterilizer I had going. I talked to the manufacturer of the product and they think that the organic chelator they are using is being broken down by the UV light? Or something to that effect.

In any case, just a heads up to those who are dosing Fe and have a UV light running which is probably few and far between on a freshwater setup...

As for the CO2, I've actually designed a fairly robust DIY system involving multiple tanks that provides some very constant bubble rates (3-4bps...even higher if I want by adding another reactor) that requires bi-monthly cycling/refilling of bottles to maintain the production rate. I have to admit, its a lot of fun to tinker and build my own stuff and "cheaper" as well.

verkion

 

[SuperColey1]

I got rid of my UV about a year ago Not for any thought about chelators (was using TPN/TMG) it was because I was not happy with having the flow restriction

Maybe that's why my tank suddenly got greener!!! I assumed it was all down to the flow improvement although knowing the TPN/TMG does have good chelators it may well have been improved flow.

AC