Watering volume, less is more???

Always water entire pot. A little runoff is fine but don't leech out what you pay for in the soil needlessly. It takes the volume it takes - you learn in hindsight only or through consistency of your potting mix and your memory from the last grow. You can find consistency by always watering at the same loss of weight - this will require a similar volume each time to accomplish the task. If you have a buildup problem, a little extra runoff is what you need to get the substrate back in the right spot, but in soil you should adjust your fertilization behaviour to avoid such things in future. In soil - wait for 1" deep of top layer to dry and repeat. If it's a half inch deep is that going to be detrimental? Nope, but do make sure there's some sort of wet-dry cycle. It helps avoid pets and pathogens. The why: It has to do with how roots physically grow and how the soil will dry out. Using proper habits, the roots will grow deeper and less superficially. You'll better avoid pests that lay larva in the top few inches of soil with a good wet-dry cycle -- I'd recommend keeping Bti handy and pre-emptively use, but that's up to you. Incomplete watering can result in a dry pocket or zone in your pot beneath the surface. Being dry it might repel the water of future irrigations more than it's sorrounding and remain dry. That ebb and flow around edges will continueally deposit fertililzer (whether it is "salts" or organic or not, lol) and it will become a toxic buildup at some point (a needless risk but not a guarantee). Soilles is similar but different. 10% runoff each time and always fertilizer well-balanced diet between1.3-1.5EC, give or take. the runoff in this context maintains equlibrium in the substrate and never needs a flush, but may need a formula adjustment until you find teh goldielocks zonen that works for nearly all plants seed to harvest with minimal adjustment. That equilibrium is never what you feed at, but it is consistent, and consistency avoids buildup and other problems. Makes diagnosing leaf symptoms more confident and easy. the adjustment to formula will reset the substrate very quickly to new equiibrium levels within a fertigation or two... or give some extra runoff to hasten the process. ---- future reference - top off any potting soil mix up to 50% of volume being drainage-related amendment. perlite #2 or #3 (bit too chunky for me), vermiculite #3 and pumice stones are all viable options. The grades give a general size you want that allows air to penetrate better and better drainage but doesn't physically impede roots too much. This may cause you to water more frequently than before, but it will be nearly impossible to drown the roots. Coco only needs 33% drainage amendment choices due to lower water holding capacity per volume compared to soil or sphagnum peat moss.