Nutrition Rates Differences Between Agricultural And Aquatics Fertilizers

Charlie87

New Member
Sep 7, 2020
4
2
3
Cuba
Hello Every one
I'm from Cuba. Here there is no market for planted tanks and we don't have access to any commercial soil, lights, or fertilizers. I'm doing some testing with a few agricultural fertilizers, homemade substrate, DIY Co2, and 6500k led lights. I'm getting decent grow at least for a basic planted tank. But I need some help to fine-tune the dosage of the fertilizers I have. To try to get the best of them. Then I'll try a better setup
Here is impossible to have access to KNO3, CaNO3, or KSO4, so that's out of the question. And my tap water is about 380ppm or 800 micro siemens.
What I have been dousing is:
Urea
KCl
Fe DTPA
and an NPK with these percentages:
N 19%
P2O5 19%
K2O 19%
Mg 0.16%
Fe EDTA 370ppm
Manganese EDTA 185ppm
Zinc EDTA 55ppm
Copper 40ppm
Molybdenum 25ppm
Boron 100ppm

The main problem I find is that I can only find on the web the macros amounts based on NO3, PO4, and K. But what I have is based on N, P2O5, and K2O
Any help to figure out how much N, P2O5, and K2O for a medium-light aquarium will be great. Thanks in advance.
 

Zeus

Lifetime Members
Lifetime Member
Oct 20, 2016
53
16
8
57
Yorkshire,U.K.
Hi Charlie,
Any chance of getting a water report from your water supplier?

Have you got a pic of the label of the product your using with the data analysis on it or a link to the product your using would be helpful too. Should be able to convert those %w/w to ppms and we can work from there. Just need some more details and we can work out a suitable DIY mixing/dosing regime to suit ;)

I take it that the
Urea
KCl
Fe DTPA

are slats you have got your hands on, whats the Fe DTPA percentage ( not that it will make a massive difference)

Cheers,

Zeus.
 

Charlie87

New Member
Sep 7, 2020
4
2
3
Cuba
Hi Charlie,
Any chance of getting a water report from your water supplier?

Have you got a pic of the label of the product your using with the data analysis on it or a link to the product your using would be helpful too. Should be able to convert those %w/w to ppms and we can work from there. Just need some more details and we can work out a suitable DIY mixing/dosing regime to suit ;)

I take it that the


are slats you have got your hands on, whats the Fe DTPA percentage ( not that it will make a massive difference)

Cheers,

Zeus.


Hi Zeus
Impossible to get an analysis of my water. The water is just pumped from a well, at1 km, for all the neighborhood. They add some hypochlorous acid (HOCl) but I wait more than two days to use that water. So I assume it already evaporated. I have a TDS meter, that's the only test I've done.
Mi Fe DTPA is 11%
everything I have are salts, yes.

I try to find some more specific data about the product on their web. But what I got is a tailor-made product. The information in the bag is what I listed above whit % and ppm. A pic of the bag is attached. The salt is reddish, so I assume it contains potassium chloride as a source of potassium.

I found that I can calculate the amount of nitrogen from the Urea and the potassium from my KCl with the rotala calculator. But How much nitrogen I need to dose to get the levels of nitrate I always heard to talk about? And how I can calculated the amounts of P2O5 to reach the levels of PO4 that I need?


Thanks in advance :)

photo_2021-04-21_09-02-15.jpg
 
  • Like
Reactions: Zeus

Zeus

Lifetime Members
Lifetime Member
Oct 20, 2016
53
16
8
57
Yorkshire,U.K.
How to convert ppm to percent, so pretty straight forward, 370ppm = 0.037%

Having done the IFC Aquarium Fertilizer Calculator with @Hanuman it was pretty straight forward as we are use to dealing with N,NO3,NH3,PO4,P2O5, ppms , %w/w etc. So added the data and played around with what would be a suitable dose without having anything in great excess

Adding 1.2grams per week to 100litres of water yielded 3.31ppm PO4 which is the upper advised limit for full EI dosing

comparing that dose with EI dosing and TSN

upload_2021-4-22_19-56-49.png


So as tempting as it might be to add some extra Fe to make up the more suitable this may result in some other trace element deficiency esp when we compare with TSN delivers at a standard dose with what GATIT would at 1.2grams per 100litres

upload_2021-4-22_20-1-46.png


Increasing the dose and the PO4 and NO3 levels do get a little on the high side
upload_2021-4-22_20-4-45.png

and trace side is still a little low IMO

upload_2021-4-22_20-5-39.png


Obviously the crop they use it for has high N and P needs.

So I would be reluctant to advise using GATIT for your tanks needs :( as to get the trace elements at reasonable levels you will be dosing high [NO3] and very high [PO4]

If can get your hands on any other ferts just post and will see how suited they may be.
 

Charlie87

New Member
Sep 7, 2020
4
2
3
Cuba
So I would be reluctant to advise using GATIT for your tanks needs :( as to get the trace elements at reasonable levels you will be dosing high [NO3] and very high [PO4]

If can get your hands on any other ferts just post and will see how suited they may be.

Thanks, Zeus

I'll keep looking for some other way to add some traces. As I can see, I can cover de macronutrients and the Fe dosing with what I have:
Urea
KCl
Fe DTPA 11%
Gattit

I will use about 1 gram of Gattit in 100 liters and fine-tune the nitrogen, potassium, and Fe with the rest of the salts. My water is from a well, so it may be some trace there. Probably it would be enough to grow easy plants with a lot of water changes.

How will affect the amount of chlorine to fish and plants if I add to much KCl? Like 7 or 8 ppm of Cl. I reed Cl is good for plants but I didn't found the critical amount or the toxicity levels on planted tanks.

Great work with the calculator by the way! I plan to used it a lot from now on.

Cheers
 
  • Like
Reactions: Zeus

Zeus

Lifetime Members
Lifetime Member
Oct 20, 2016
53
16
8
57
Yorkshire,U.K.
I will use about 1 gram of Gattit in 100 liters and fine-tune the nitrogen, potassium, and Fe with the rest of the salts. My water is from a well, so it may be some trace there.

Just watch your plants, if they are growing well your fine, it doesn't have to be rocket science.

How will affect the amount of chlorine to fish and plants if I add to much KCl? Like 7 or 8 ppm of Cl.

If you add KCL your adding chloride not chlorine, easy mistake made by many, so 5-8ppm Cl will feed the plants. Not sure what the upper limit for Cl is but I would of thought its well above what your dosing.

Great work with the calculator by the way!

Thanks, I started it to make life easier for myself, was requested a copy cleaned it up a bit, got help from many others esp @Hanuman and what you see is a labour of love and a lot of time from myself and Hani, always good to share esp if it makes life easier for all. We are always looking for new products to add so drop us a pm if you come across any :)