Disappearing Fe/Iron absorption rate of plants?

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

 

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!

 

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

 

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!

 

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