Not breaking any rules Smokey79, I find with any medium that uses chemical nutrients, you must water to runoff. Personally I do almost 50% runoff because I make my own nutes so it is literally pennies.
Chemical nutes are very much simply salts in the water. If you fertilize with no runoff, there will always be evaporation of the water leaving it slightly saltier each time. Eventually it may rise to toxic levels. The less amount of runoff you have, the closer you have to monitor how much salt buildup you have in your medium.
I had some plants in soil with about 20% perlite. (this was when I was first starting out) I fed a max of 1.3EC throughout with about a 5-10% runoff.
never bothered checking the runoff EC till the flush.
I flushed that first plant out and checked and the EC was 2.8 Luckily it is a very tolerant plant. I flushed it thoroughly with plain water till the runoff was very low and gave it an extra week to allow the internal nutrients to lessen.
smoke was still very good but later I realized that the smoke could have been amazing if I had only paid attention.
Gotta get some sort of drain pan in the tent and test runoff occasionally. Some will say runoff EC will not matter but if you are putting in 1.3 and getting out 2.8, you know that the growing medium is pretty darn hot!
