# "The case of the missing iron… "



## Walker_ (Mar 24, 2006)

Hi there, just new to APC looks like a great place!!!

So here’s the situation; I am just getting into plants for my tank, so I did some research and picked up some hardware. For reference this is a 90gal, using 100% fluorite, 2x400w metal halides, and Co2 with a PH control. My plants seem to be growing fantastically well, and I am getting great pearling off of everything. For fertilizer I am using Tropica master grow, seachem Iorn & Seachem nitrate. I can dose everything up to the levels that I have seen suggested (.5mg/L Iron, 30mg/L Nitrate) but after only 6-8 hrs all my levels are back down to zero… The brand new bottles I picked up not more than 4 days ago are almost empty!!! 
Am I misreading my dosing and adding too much? If these are the correct amounts to be dosing is there a cheaper alternative than buying these little 500ml bottles? Maybe a powdered form that could be bought in a 10lb bag? And if so what would be a good way to introduce the ferts into the tank? I was going to try and get my hands on a retired Intervenes dosing pump from the hospital, would something like that work or is there a better alternative? 


Also in the experience of the growers here what are plants that the LFS seem to like to buy off of local growers, IE what would be a good plant that I could grow and I may be able to recoup some of the $$ iv spent on all this gear…

Thanks everyone!
-walker


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## Laith (Sep 4, 2004)

Welcome to APC!

Yes, there are alternatives to commercial products for nutrients. You can purchase KNO3, KH2PO4 etc in powder form from Greg Watson at www.gregwatson.com. Don't know where you're located but he can ship almost anything except for KNO3 worldwide (KNO3 only within the US).

Otherwise certain stump removers are also KNO3. PO4 can be dosed using Fleet Enema. I've never used these two products so can't comment on them. I get KNO3 and KH2PO4 from my pharmacy.

800w over 90g is *alot* of light!! Why are you using so much (2.5 to 3.5 or 4 watts per gallon is more than enough)? It'll just drive the plants that much harder and make it more difficult to ensure sufficient nutrients in the tank... You're walking a razor edge with that much light: a slight imbalance and algae will love you forever!

As to dosing, I mix powdered chemicals in water and then use dosing pumps to dose. Do not mix Iron with the PO4 as Iron and PO4 have a tendency to precipitate out as FePO4, especially in high concentrations. I have one container with macros (KNO3 and KH2PO4) and another with micros (currently using Flourish and Flourish Iron but am going to experiment with Tropica Master Grow).


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## DubSack (Mar 20, 2006)

ya, like Laith said. Greg wattson dry ferts are by far the cheapist. I've have my ferts for over a year and I havent even made a dent out of the 1 Lb bags. A 50$ purchase will supply you with enough ferts for the next 10 years.


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## Krisybabe9 (Mar 21, 2006)

Here is a question for you...Are you using activated carbon in your filter? The carbon could be filtering out your nutrients. Though to what degree, I am not sure. Also, I agree with Laith regarding your lighting...that is A LOT of light! I would scale that back asap because as Laith noted, the plants are fighting to gather nurtients (which could also be the reason your nutrient levels drop significantly so fast). Good Luck!


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## Walker_ (Mar 24, 2006)

Well thanks everyone!
I just ordered a load from Greg so hopefully Fed-EX wont take too long! NO I don’t have any carbon at all; All I am running is one MASSVIE DIY canister (40gal) filled with lava rock; and a Diatom that I only run once and a while…. Any suggestions on the light then? I take it I cant just put a 250w bulb in a 400W ballast….. would just turning it from 12 hrs down to 6 hrs be enough?


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## taekwondodo (Dec 14, 2005)

What test kits are you using?


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## Bert H (Mar 2, 2004)

Don't bother trying to accurately measure iron. Between the quick plant uptake, the fact that it can precipitate under certain conditions, and the inaccuracy of the test kits, it's not worth trying to measure it. Go by your plants.


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## taekwondodo (Dec 14, 2005)

agree on the iron testing, but it seemed he was saying his NO3 was dropping to zero in a few hours as well - smells like bad test kit to me...

If he's dumping in NO3 and using a bad kit, he could easily be wasting money and overdosing...

- Jeff


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## MoonFish (Feb 12, 2006)

Holy mashed potatos batman! Yeah I would maybe cut back from 12 hours with 800 watts


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## Laith (Sep 4, 2004)

Walker_ said:


> ...would just turning it from 12 hrs down to 6 hrs be enough?


Unfortunately the relationship between light intensity and light duration doesn't work like that. You can't increase the amount of lighting by increasing the duration and vice versa.

Not sure if you can just replace the bulbs. Anyone else have input on that possible solution?


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## titan97 (Feb 14, 2005)

Seachem also sells most (if not all) of their products in 1L, 2L, and 4L quantities. Check out www.bigalsonline.com. You should be able to grab all the Iron and any other products that you need a little cheaper than what you get in the 500mL bottle. 
I have a very high light setup (10WPG) and I don't have an algae problem. As long as I dose my NPK and micros, I am fine. I also toss in a few mL of Excel once a week just for good measure, too. Granted, if I slip up or I am away on the road (working), I can and do come back to some algae. It can be done, but it takes more work. 
Have fun.

-Dustin


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## Bert H (Mar 2, 2004)

> Not sure if you can just replace the bulbs. Anyone else have input on that possible solution?


 I don't know anything about MH's but it would make sense, just use lower wattage bulbs and you're there.


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