Kramerdrak in EI dosing

[jsiegmund]

Hi all,

I'd like to check with you guys whether the calculations I'm doing are ok or not.

At the moment, I'm using Kramerdrak as fertiliser instead of a self made EI mix. The why behind this is pretty simple: I still have two bags of it lying around and it would be a waste of money to just throw them out. So I thought: let's see what's in there and see how much I need to add to come up to EI levels.

So in the "what's in there" department, I found this:

Weekly quantities added by a dose of 10 ml/week/100 l

2.1 mg/l potassium, 344 µg/l magnesium, 187.5 µg/l iron, 71.5 µg/l manganese, 9.2 µg/l copper, 8 µg/l zinc, 7 µg/l boron, 4.3 µg/l molybdenum, 2.5 µg/l cobalt, 0.66 µg/l lithium, 0.65 µg/l vanadium, 0,63 µg/l aluminium, 0,63 µg/l nickel, 0,6 µg/l selenium, 0,53 µg/l tin

Okay, so that's no mystery at least. From Clive's post, I extracted this information:

Nitrate (NO3) 20ppm per week.
Potassium (K) 30ppm per week.
Phosphate (PO4) 3ppm per week
Magnesium (Mg) 10ppm per week
Iron (Fe) 0.5ppm per week

Cool. My tank volume is 240 liters, I think my filter volume compensates for substrate and rocks, so just left it at 240. Now I calculated that I would need a dose of 70ml / week to get my Magnesium and Iron up to par. That leaves Potassium low (6.125) but both my phosphate and nitrate solutions also contain potassium which should be enough to compensate.

So now my question is: does this make any sense, or am I forgetting something? Again, I understand it's better to just use EI solution but I'd like to finish up with what I've got in the best way possible. It's the same elements in there (maybe different dosages) so it should be possible imho. The weird thing is that on their site, Drak lists that adding more than 15ml / 100l weekly does not bring any further improvements. With 15ml you're not on EI levels I believe, so why would they state that if it actually hurts their potential sales? Weird. Anyway, if someone could validate this, that would be much appreciated. Thanks!

 

[xim]

May be it's like Tropica's liquid fertilisers' instructions. Which generally suggest quite a conservative amount.
Because most tanks don't have many plants or get frequent water change. But for “our” kind of planted tanks
that amount is usually not enough.

Have a look at this 200 litre tank done by Tropica themselves. If you follow the instruction, the dosage
would be 20 mls per week. But in reality this tank gets 200-300 mls per week.
http://ukaps.org/forum/threads/a-little-inspiration.29865/

 

[oviparous]

There is nothing wrong with Kramerdrak. I would even say it is better than most micro fertilizers because it uses stronger chelates. That way the iron stays longer in solution and is available for the plants.
Dosing 0,5ppm of EDTA iron is less efficient than dosing 0,5ppm DTPA/HEEDTA iron. EDTA is going to break down much faster, so the usefull % of iron is much lower. Mg is also chelated with Kramerdrak.
I have been using Kramerdrak for a long time and dose a little bit more than the recommended dose in an heavily planted tank, and never had micro deficiencies.
This isn't about numbers, but what your plants need. If you see deficiencies, dose more.

 

[dw1305]

Hi all,

So now my question is: does this make any sense, or am I forgetting something?

Should be all right, for soluble salts once they are in solution "an ion is an ion is an ion", it doesn't matter what compound they originated in.

Chelates are a slightly different argument, as "oviparous" says some chelates are more efficient than others, dependent upon pH etc.

This isn't about numbers, but what your plants need. If you see deficiencies, dose more.

That is my approach, but I'm low tech. and dosing at rates a fraction of those you would use for EI.

cheers Darrel

 

[jsiegmund]

Okay, thanks guys. I've increased the dose to match, should be plenty of food now. Let's see what happens