How much Basalt?

First post ,so greeting first of all,,

Am going to be adding basalt as the only rock dust to my mix,,just not sure how much,

This is the mix its basically 1-1-1

100 litres/27 gal. Perlite
100 litres/27 gal. Soil ( half horse manure half garden centre substrate)
100 litres/27 gal Coco+worm humus (70/30)
1kg 4-8-10 organic granulated fertiliser (smells like blood fish and bone meal mix)
1kg dolomite ? Is Really necessary? Have not bought it yet
1kg guano ( already have from previous grows but wont be using again,)

depending how it feels will probably add another bag of base soil,,
this will be used out gorilla style so dont really want to feed ,maybe top dress if needs be,Will mix up and store for next year,,

anything stand out as blatantly missing or out of balance ? Any feedback appreciated

how much basalt would you use?

I would use 2 cups of basalt per cu ft of base mix, which in your case comes to basically 20 cups of basalt. I don't use dolomite but I dont think you'll need it for water only and you dont have peat moss, but i'd wait for someone more knowledgeable than myself to chime in. You have your base listed by volume by your ferts listed by weight, so i don't know how to determine how the proportions are there. Could you give me volumes for your fertilizer and guano?

Yeah my bad never thought,,
1kg bag guano is roughly 3 cups,,,
The fertiliser would be easy double that but I haven’t bought it yet,,its cheap enough so can add however many cups is recommended,,

also forgot to say I have some epson salts ,would it be worth adding some or will the basalt give enough magnesium? the basalt ive got comes in at 10.74%

thank you for the advice! Appreciated

If your not going to use any other amendments, I'd go with 2 cups per cuft of base mix on that fertilizer mix

Thanks for that,

Generally,, when adding amendments in cups per cuft of base mix,,is that before the aeration is added,( as my perlite is 3.5 cu ft.) Or the total mix? Excuse the ignorance just don't want to add say another 7 cups of something .

lots of other amendments I would like to add ,but will keep adding year on year as funds allow,,

cheers!

That includes aeration. Base mix is usually peat+compost/ewc's+aeration