In my experience with ebb & flow, enzymes and drip clean solve the high tide salt ring. But you have to use drip clean from the beginning of your crop. I have seen where someone put out a shitty crop by starting drip clean in middle of flowering.
I use Carefree Enzymes Pond Protector Stage 2. It is 15 mls/100 gals. So my quart will last for over 6000 gallons. I have been using this stuff for a year and a half. I have saved so damn much money vs.
hygrozyme.
Hygrozyme's prices are wack.
The Carefree people even have a 'hydroponic formula' with enzymes stated to be tailored to reservoir use. I have not used this yet, and don't know anything about the proposed application rate.
It was Jalisco Kid's posts that first turned me on to this enzyme source. I like how he will make you dig for a while to find the thing he talks about. It separates the committed from the rest.