# DTPA Dosing frequency



## ctyank (Oct 23, 2006)

So I received 11% DTPA from green leaf aquariums a couple days ago.

http://www.greenleafaquariums.com/aquarium-fertilizer.html

I clicked around the forum, saw some dosing regimens and did some math and I decided to add about 1.5 grams (in solution) to my 180G tank. I'm just not sure about frequency. EI is out of the question in a 180G. Actually tried it for a bit. The water bills were unamusing.

It seems that most posts suggest that the chelated iron breaks down rather quickly... but nothing much more specific than that.

So my 180G is densely planted, with plenty of CO2 in fairly soft water (gH about 7... <2 out of the tap... Durham, NC water is very, very soft). Amazonia substrate.

Thoughts on frequency here? Thanks!


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## OTPT (Sep 27, 2010)

I think no one can pinpoint this. There are at least two factors involved. 
KH of your water and uptake rate of your plants. 

BTW, my house use approx 55,000 litres of water a month.
My tank is 350 litres (around 90 US gallons). Changing 50% 
a week is just 175x4 = 700 litres. Or 1.27% of water bill.


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## ctyank (Oct 23, 2006)

Alkalinity/dKH of water around 4 (I have to add baking soda to get it that high). 

Uptake of plants is not measurable in any case. I'd guess pretty fast by the amount of pruning that my tank requires. 

As for EI on a 180G... or a 90G for that matter. Sigh. I get that a lot of people like it. I get it has an upside. And for a 20 or 30 G tank, I love it. But honestly... do any of you have indoor faucets that put out more than 2 GPM? And are you putting water directly in a tank or staging it first (so you can add Prime or Novaqua or whatever)? So draining 90 gallons: at least 40 minutes using a python. Getting 90 gallons into a staging area at least 45 minutes. Then pumping into your tank... at least 20 minutes. So two hours for a water change on one tank. Every week... Kill me now. 

(Note that I respect the dedication put in by maintaining EI on a 90... I'm just not up to it.)

And what does it buy me? I have a plant-loaded tank scrubbing nitrates and phosphates out of the water. It doesn't need to be changed for the critters. So the whole benefit is so that I can trust the math of EI and dose blindly. 

Nah. I tested for Nitrates and found that if I put in a certain amount (2 teaspoons KNO3) per week, my tests come back constant. Phosphates covered by fish food. Potassium probably covered by the KNO3, but I add some Potassium Sulfate to be sure. Which pretty much leaves me with needing an iron schedule. I guess I can test, but Fe tests are confusing at best.

So let me ask this another way. For those of you with larger lush tanks NOT following EI... how often are you dosing DTPA?


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## wet (Nov 24, 2008)

Never had a big tank, but I'd suggest picking up something like Elatine triandra, H. micranthemoides. Mayaca sp,, Ludwigia sp 'Guinea', Polygonum sp, or another species that tends to change color quickly with micro/Fe limitation, then use that to drive your dosing frequency. On a high light/uptake and healthy tank I liked daily dosing of Fe. 

nfrank is from around your parts and I recall him finding weekly dosing of Fe from good chelators (Tropica) adequate. I think he's more a big slower growth tank filled with Anubias, Swords, Crypts, Java Fern type guy most the time though. 

Let your plants drive your trace dosing and I think you'll find you tune it nicely quickly.


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## bosmahe1 (May 14, 2005)

I add micros daily to about .18 ppm of Fe. My micros are csm+B and dtpa at a ratio of 4:1. You might try going straight from tap to aquarium. you don't need to pre stage your water. Just dump the de clorinator in the aquarium as the water is flowing into the tank. Just make sure you adjust the water temperature slightly cooler than the aquarium temperature. Most people with larger tanks do it that way I think.

Follow this link for different methods. I built something like what is pictured in post # 26 except I use 1/2 inch clear tubing that is attached to a shower.

http://www.plantedtank.net/forums/g...ussion/115061-lazy-water-change-method-2.html


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## ctyank (Oct 23, 2006)

Thanks for all of the advice!

WET:
I'll look into the indicator plants. Love the idea. Neil Frank is actually part of our club. I think you are right about his setups. He is always bringing us nice swords. I have one of his in this same tank.

bosmahe1:
Going from the tap to the tank (once operational with fish) has like never even occurred to me. And as I sit here and think about it, I think I know why. About a year before my very 1st tank, I was at at a relative's house during one of his water changes. Not sure if it was human error or a small water heater, but he accidentally put COOOLD water in the tank. Pretty sure the event caused some fish mortality. That was 1986. I've been staging water ever since! Habits man... hard to break.

So if I'm adding 40G directly to a 180G tank, am I "dosing" PRIME for only 40G worth (4 ml)? Or do I use more?


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## bosmahe1 (May 14, 2005)

ctyank said:


> Thanks for all of the advice!
> 
> WET:
> I'll look into the indicator plants. Love the idea. Neil Frank is actually part of our club. I think you are right about his setups. He is always bringing us nice swords. I have one of his in this same tank.
> ...


I've heard where you only need to treat for the volume being added. Since your tank is that large, I think that should be perfectly safe. I would probably add the water and two capfuls of Prime (10 ml) at one end of the tank to allow it to mix before spreading throughout the tank.

That being said, I toss a capful in for my 46 gallon bowfront since Prime is inexpensive and with a smaller tank, it might be more critical. My fish are used to the water changes, they enjoy swimming in the cooler water and don't seem to mind the Prime and whatever chlorine that might be detectable. I haven't lost any fish doing this. It kind of makes my feel silly for carrying buckets for 6 years.


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