Some varieties are more prone to this. 'The King' is one that does it for me. Probably more than one reason. In my experience - soil is old, pH of soil is low, it cannot absorb nitrogen.

Second possibility - water should have something - so if it is not chlorine - it is chloramine, which is much worse.

Drench the soil - the totally perfect solution - will be several drops of fish emulsion per gallon of distilled water. Cheapskate solution - that's me - drench the pots in a sink with tepid water until it runs clear. Let them drain on a stack of newspapers. Repot the darn things - removing old leaves - they are not going to green up ...ever. Repot with minimum disturbance to the rootball - trim the bottom of the rootball, scrape the top a bit, add soil to the bottom of the pot, add the soil to the top until it will cover the bare stem.

Thanks. I am growing to sell, so have manyyyyyyy in a greenhouse. I have to figure out how to fix this so it doesn't keep happening.

Then - do plan 1 - drench with fish emulsion, remove the most offending lower leaves - and sell them. They probably will go into bloom soon anyway.

The warmer is your greenhouse - the faster peat in the soil goes acid.

Test does say free and total. But not chloramines. We are on well water.

I do not believe you can reverse discoloration - but you can stop it from progressing. So - drenching with a fish emulsion - and add 1/8 of teaspoon per gallon of Epsom salt in your water from now on. What is your water pH?

Ph is just a tad high and chlorine is lowww, I will add the epsom salt to my wicking water. Its so sad to see these growing so beautiful and ready to sell, then I have to cut off all the huge leaves that are rimmed in yellow, then the poor plant shrinks. All most all are noides, and some don't have this problem, but most do.

Hmmm... we had snow yesterday... usually it means that nobody buys AV's...

I am in CA, we have sun, lol.