[fattboa]

Originally Posted by dantra

Thats what Tom said. You can read about why some opt out of using Urea here where Tobi intoduced is mix originally at UKAPS. This is a quote from Tobi's instructions:

I'm producing ferts commercially (Aqua Rebell and sell them through my shop "Aquasabi") for people who do not want to work with all those chemicals.
But here is the recipe for the new nitrogen fertilizer, i've posted it at my community http://translate.google.de/translate...4.html&act=url too:

for one liter water add :

25,9 g potassiumnitrate
29,5 g calciumnitrate
17,6 g magnesiumnitrate
5 g urea ( :arrow: your tankwater pH should be <7 to avoid problems with ammonia)

That will add 1 ppm NO3, 0,2 ppm K, 0,1 ppm Ca and 0,033 ppm Mg using 1 ml per 50 l tankwater.

Here is where you can order Tobi's mix

I've read about this about a year ago but I couldn't use urea because my pH is north of 7.0. The mix isn't new and was tried in the past but if Happi "improved" on it a bit then I say have at it. Just be very careful when using Urea. I think the focus is more on getting the nutrients to your plants that they are lacking.

I'm in Texas where the water is basically liquid rock. Now one would think that I have enough calcium and magnesium because my GH and KH are through the roof, most of the times north of 14 sometimes as high as 22. What I discovered was that the water is very rich in calcium but had very little to no magnesium so when I started adding just magnesium the plants perked up and took off.

Just like in the UK, the water is rich in calcium but has very little magnesium in some places so when they started adding magnesium the plants reacted in a very positive way. If your plants are getting the nutrients they need and are none-limiting, no amount of Urea is going to change that. Just be careful and enjoy the plants

Dan

I did buy one kilogram of urea but I have yet to use it. Maybe I will experiment a little. Currently trying synthetic auxins (NAA/NAD) at around 10-9M (or at least I hope). My pH is also north of 7 and I am aware of the issues but need to look at a few graphs regarding disassociation vs pH to gauge the danger or risk. I don't think all of the NH4+ will convert into NH3 just as you reach a pH of 7, perhaps a bit more? Interesting, the water (desalinated seawater really) around here is also very poor in Mg yet high in Ca with but also soft I believe. Could not find any good kits and not bothered to test at the university (too many questions asked)
I do find some very interesting products around here, like this one: http://www.chema.com.eg/SpcialFertilizers.html scroll down to Elodia* (sic) which reminded/lead me to this while searching about allelopathy a while back: https://docs.google.com/viewer?a=v&q...Ll0KOdPpBM2WQ7
Which coincidentally is also done in Germany! Those Germans love aquatic plants. I only read the abstract and skimmed the paper so apologies if it is not related.

Originally Posted by happi

Tobi also stated K+ stunting the plants, this is not true at all, plant need K+ more than any other things, IMO it should be always higher, least 3 times higher than the Nitrogen. Tobi also have taken out Urea from his fert, while i think Urea is the main player here for fast plant growth.

am not working with Tobi's fert or trying to modify it, this is not even related to his fert at all, am working on this fert based on the research i been doing on plants, how they respond to differnt sources of nitrates etc.

someone told me to use Mg sulfate and Ca sulfate to get same results but IMO it have soulibilty issue when adding in the solution, Mg and Ca nitrate were the only good source to work with. its not only the nitrate which is important here, but Mg and Ca are more important.

I wish you good luck.