I am choosing screens to buy for sifting the gritty mix ingredients. I like the idea of this kind of screens: http://goo.gl/HJCNF. They fit on top of a standard 5 gallon bucket and can nestle if screening 2 sizes is necessary, like with bark. I do not have outdoor space, so the idea of a snug fit is great to minimize the dust.

However, they do not come in 3/8ths mesh - only half or quarter inches. 1/16 insect screens are also not available in this form - only 1/12 or 1/20.

I can use this (http://www.gardenershub.com/garden-sieve-38-w1370) for 3/8ths and an insect screen from one of my windows for 1/16th, but all these screens would then be of different shapes and sizes, so no nestling convenience and more dust.

How important are the exact 3/8th and 1/16th mesh sizes for prepping the gritty mix? Can I get away with using the next available size? Should it be smaller or bigger? Would the behavior of the mix be much different?

My ingredients are Agway pine bark, Napa Floor-Dry and Manna Pro Poultry Grit. All plants are indoors, almost all tropicals, light is diffused, almost no direct light. I tend to overwater (hence the attractiveness of gritty mix) and ideally I would want to check if plants need watering every 3-4 days, not more often (I know not ideal, but I am balancing my needs with the plants'). I'll have about 35 pots to gradually transfer to gritty mix. A couple pots are 10' wide, the rest smaller - so that is how much mix I'll be preparing.

In light of all this, is it ok to deviate from the screen sizes Al recommends, or would you go for the exact recipe and inhale some dust if you were me? (I am going to wear a paper filter mask in any case).

This post was edited by greentoe357 on Tue, Jul 9, 13 at 13:53