Backyard Aquaponics
A place to discuss aquaponics

Hi all,

This is my very first post, hoping to get some replies and still finding my way around. I'm about to enter the AP realm and already have my first question.

I'm going to dig (yes, dig) laterite fom my garden to use as growbed medium (believe it's pH neutral). Do I use ecological soap to wash it and then rinse, or just rinse?

Thanks!
Los Wookie

Bump.

Welcome to the forum, Wookieman!

Google tells me that laterite is a type of rocky soil, but I'm guessing you're just going for the rocks? It'll take a lot of washing to get it clean enough to use in aquaponics, but if you're up for it I'll be over here cheering you on! As for your question, don't use soap; you don't want it getting into your water, the fish and bacteria won't like it.

the chemical composition of laterite varies and depends a bit on its origins and climate.
Laterite gravel in Western Australia for example is supplied via many landscape suppliers as 'pea gravel' and is OK - it tends to have a high iron content. Some laterite gravels are associated with bauxite (aluminium). Mostly laterite is fairly inert so it shouldn't create pH or chemistry issues. Its main drawback would be its weight and it absorbs & retains heat which may not be so good in hot climates.

As a test put some gravel in a bucket of water and see if it changes the pH.

The process would be to have a seive or a mesh of some sort and ideally do it while everything is dry.
Get a bulk of the gravel separated before doing any washing. If you go with a mesh size of around 1cm or so it should be quite efficient - especially if you can set up some form of agitation and have it rolling down a slight slope so you can feed it. Getting it free of clay/dust is the main challenge.

would be good if you could post some pictures (explained how here -> viewforum.php?f=4 )

p.s. the typical stuff around here is shown if you google 'laterite gravel' (pea gravel).
Have used it but tend to find it is best when fully submerged.
It is an alternative to blue metal (small granite) which many members use.