Yellowing leafs/overwatering/nute deff

Watering... 1) fully saturate 2) wait for dryback and repeat. As long as you aren't watering too frequently, it's incredibly hard to overwater. fully saturating should never cause a problem as it is the correct way to do it, otherwise the drying pattern trains roots to grow superficially as they turn upward toward greater moisture when you partiallly water. If any droop occurs after an irrigation, you should add more perlite next grow cycle to avoid it. don't try to use inductive reasoning. watering is simple observing and reacting at the right time. Loss of weight or dryness of top portion of soil is your trigger. You neither choose the volume to give nor the increment of time between. Facts dictate how much you need to give to get the job done and when to re-irrigate. follow this and overwatering is impossible. IF this is soilless, also give enough for a minimum 10% runoff. The leaf symptoms coincided with a fertilizer change, so i'd look at that first and foremost. You've got paling tip-in on leaf and bottom up on plant -- low N or something is impeding N New growth looks like it has slightly skinny blades and maybe some chlorosis? not the best angle of pics to see, but if that is true that hints at too much P or K from recent formula shift. the top 2-3 nodes of some colas look a little tight, so it could also be slightly too much light causing chlorosis in new growth. Cross reference as much info as you have available to you. Diagnosing based on leaf symptoms alone is indiscrete and leads to errors. if allowing anything to progress makes diagnosing more confident, be patient where you can. Doing something useless only compounds the problems. Easier to add than take away.