Creating my own fertiliser

[UweM]

rain water 80l + 8ml (~1 teaspoon) Ca-N (17-3) fertilizer + 16ml (2 teaspoons) liquid ocean fertilizer (1-3-5 NPK + many micros and others like natural hormones) + 8g (1 teaspoon) NH4NO3+MgSO4 (70%+30%, homemade)

an interesting fertilizer.

What do you mean with "liquid ocean fertilizer" - do you have a link?

 

[Paul]

this is a liquid fertilizer with kelp extract + some organic and inorganic

http://www.hydropassion.eu/index.php?option=com_katapult&task=view&id=4&Itemid=27

you will probably find similar fertilizer depending on your country

 

[Brabantia]

this is a liquid fertilizer with kelp extract + some organic and inorganic

http://www.hydropassion.eu/index.php?option=com_katapult&task=view&id=4&Itemid=27

you will probably find similar fertilizer depending on your country

You do not use anymore "Alga Mix"?

 

[Paul]

The product was not yet available, and texture is more solid than liquid so not easy to use... but very good product however!!!

 

[Brabantia]

The product was not yet available, and texture is more solid than liquid so not easy to use... but very good product however!!!

A disadvantage of the "Liq Ocea" it is it makes the solution acid ( at .2ml/L) which requires an addition of KOH or tap water fairly important. This is contradictory with the low K and low EC (µS) we are looking for.

 

[Bjorn]

But we are looking for a somewhat acid fertiliser solution? 5.5 should be close to ideal. 0.2ml per liter is a dilution of 1:5000 which should raise the pH by a factor of three or so. The stuff cannot have that low pH (ie around 2)?

 

[Brabantia]

But we are looking for a somewhat acid fertiliser solution? 5.5 should be close to ideal. 0.2ml per liter is a dilution of 1:5000 which should raise the pH by a factor of three or so. The stuff cannot have that low pH (ie around 2)?

When I add this alga extract to my fertilyser solution the pH decrease to 4.5. To neutralise this solution to a pH of 6 I need to add 6 drops of KOH 1M or 100 ml of tap water for 1 liter (and we have a very hard water: 44 °F). 6 drops of KOH 1 M in 1 liter adds ~ 12 mgr K+ which is not negligible.
Probably the alga extract mentioned is not a cold-pressed seaweed but an acid extract.

 

[Bjorn]

Impressively acid! Guess you are right, or they need that much to stabilise a concentated extract. Nevertheless, its simply too much acid, I agree.

 

[Paul]

After I add all the elements (Ca, MgSO4, NH4NO3, liquid ocean), pH is neutral here (almost 7). and I add nothing else in the rain water.

 

[Brabantia]

After I add all the elements (Ca, MgSO4, NH4NO3, liquid ocean), pH is neutral here (almost 7). and I add nothing else in the rain water.

Strange ... MgSO4, NH4NO3, Ca(NO3)2 are salts of week base and strong acid thus your pH must be acid. I never see a fertilyser solution which is neutral or slightly basic. Maybe it is your rain water which is basic but the likelihood is low.

 

[Paul]

no, water is pH 5.5. the liquid Ca (+N) source makes the pH going up!