"overwatering" is a massively misused term.
in soilless, irrgation is simple. Always fertigate. Always get 10% runoff or even a bit more is safe.. 10% is a minimum. This will never cause a problem. It is one of the major benefits of soilless growing -- the runoff elimantes possibility of build up over time. You can still feed too much, but fixing it is a matter of fixing your formula.
you don't need a TDS probe (converts EC to PPM poorly and inaccurately). You only need some acid or base if your fertilizer doesn't rest at a proper pH when mixed. pH balance as needed after adding fertilizer. As long as your water doesn't change, which it can, the same amount will be required each time. A massive change in formula or new products might require a different amount of acid or base to hit your target pH ... when things stay the same, it will remain the same. It's a very measurable and predictable thing - pH.
if proper watering habits above cause any negative repercussion, it is 100% the fault of the medium composition.. more perlite or similar is likely needed. For coco coir you only need ~33% of volume to be perlite. if you ever use a sphagnum peat moss soilless base, go 50%. Each will end up with same water capacity per volume, which is the gey .. the gas to water mixture.
keep track of your formula.. either weighted averages based on your dosing or calculat ppm of each NPKCaMgS... I've never used a EC probe and i tightly control and track the nutrition i give.
commented2d ago