Backyard Aquaponics
A place to discuss aquaponics

VB, I have a good friend who is a Landscape Gardener and has a masters in ag science. He has forgotten more about plants/soil etc than I can ever hope to learn.
He has used the Mineral fertiliser for years. He put me onto it about 20 years ago and I purchased a load at the time, then I moved to PNG and when I got back from there I had lost interest in gardening etc until this Aquaponic thing came along.
I still have a little of the Mineral Fertiliser left. The minimum purchase is 1 tonne.
The rate of application has been arrived at in consultation with my mate.
He spends many an hour over here salivating over my fish. (I think he is plotting something)
This stuff is of such good quality.
If you can only afford crusher dust then go for it, I sure it will help a bit.

Murray

It really depends on how much needs to be used in the system to achieve the desired result - hence my question regarding application rate. When writing the question the answer became clear anyway. In a closed system the application rate should be able to be much less than in a soil garden as the goodness will not be washed out of reach of the plants. I had intended removing water from my system to a certain degree to water soil plants and replace with tank water (rather than just watering the soil plants with tank water). Under this type of method I would have to apply more rock dust than if operating a total closed system. I may have to rethink my intended methods if nutrient deficiency is going to be a real problem - which it already is for some plants.

How long have you been using the stuff in your AP system Murray?

Posted this in Les's thread but thought it might be better here.....



Jezz Steve... Kangaroo Valley is less than 15 minutes away from me...

(It's actually hidden in between the hills in the background of my avatar)

I'll follow it up if you want and see if we can organize a 20kg bag or something which people can diffy up ....

Just a thought but remember that post I made about the farmers removing all their rocks from the soil and the productitivity would donw the tube.

They were your regular volcanic bubbly semi crumbly to really hard basalty type stuff. For those interested in food miles and all that you could just get a few of those hit em with a hammer a bit and then through them in the system. Maybe thats part of the reason why the red volcanic soils are so good to grow stuff in?

On another thought its possible you could do the same thing with a whole stack of rocks for the same effect.

Stuart.

There are postings on the net where people have successfuly just used your every day crusher dust. They just sieve it to remove the larger particles becore using the powder. Would work best if it were granite and/or basalt.

ROZ, we'll talk

yep, micro mineral deficiency is rampant in or food chain.

OK, talked to Terry @ Orchid Images.... he will do a 20Kg bag for $6/kg => $120... then of course add freight to each capital city....

So if someone wants to nominate to be the central depot in each area???

Or everyone could order the 1Kg bags each and I could consolidate them into one shipment to save on freight... Terry wont drop the price from $7.50 for the 1kg bags.

As an aside Terry says that four or five years ago they spread the product on their nursery soil and raised the pH from 4.5 to 6 in less than three months and that with very small yearly applications have been able to maintain that pH without any real effort... he stressed "small" top-up applications....

Sounds like an excellent pH buffer to me....

Rupert - yesterday I bought a mineral supplement product called Min Plus. It is crushed volcanic rock from Innisfail. It cost $13.50 for a 10kg bag from my local landscape joint/hardware. To see if there is a supplier near you, e-mail the manufacturer from the wesiteHERE.

I have posted some pics below of the packaging - which included mineral content analysis. Different products of this nature contain different levels of oomph - but as we don't need that much in our systems (being closed an all) I think the Min Plus product will be fine.

Good one vb, noticed there is a place on the northside (Bris) so might pay them a visit shortly. I have been trying to source something that had a little extra than what chelated iron offered - let us know what dosage you start at, I would work on the conservative side and possibly add on a monthly basis

I put in 100 grams to my 500 litre gravel bed. I will watch for the next couple of weeks to see if there is any noticable difference. I mixed it with some fish tank water and then applied it with the waterring can. I then applied another can of water so there was not too much of the stuff left on the leaves of the plants. Rain over the next couple of days will further help to wash it into the bed.

I took KH and GH measurements this morning - so will know if this stuff changes those at all. I have plenty of CaCO3 in the system at moment and PH is very stable, so I didn't really need help in this area anyway.

VB, expect the GH to go a bit due to the magnesium content

GH is already 25 dKH. Sometime soon I may be forced to do a big water change to bring GH down. Keep meaning to test my tap water for KH and GH content. Pretty sure KH is 0, but GH might be higher.

run a few plantings of plants that are high in calcium / magnesium...........obviosly these plants uptake and bind Mg and Ca more than others................yet another extension of the BALANCE

I took readings of the tap water. Have placed results on my system thread HERE.

I seems to me like it might be important to start with rocks that contain all the necessary minerals. My simple understanding of soil is that it is made from rocks -- rocks eroded by water, air, chemical reactions, and the action of bacteria, fungi and plants. So simplistically, the whole world is a (solar-powered) AP system and the dirt of conventional agriculture is just thick biofilm (or at least it was biofilm at one time)

It seems like it might be worth getting our gravel analyzed for mineral content and then using rock dust from another area to enrich defficiencies. And in my case -- using groundwater from a well -- the water contributes some minerals -- chiefly calcium and magnesium in my case.