PPM drifting up, plants drinking just water , how to flush

im in day 2 flower. ppm at 300 for the last week but the ppm is always going up by 10 each day . plants are 20 inches tall . i havent upped the ppm's yet cause it seems the plants are just drinking water .as the ppm goes up i add fresh RO to my res bringing it down to 270 but it still goes up . what am i doing wrong ? im changing the res today , should i give them some feedings with plain RO ph 5.5? to flush them . anyone help ?

P.s 2x 4x4 flood and drain tables growing in hydroton. PH 5.5to6.0 . 9 on each table, 300L res .Sensi bloom AB

shouldt the ppm be going down , meaning add more nutes?

How big is your reservoir and how much water are you adding back daily? When you say you add water and it just goes back up how fast is that happening, like the next day? Sorry, didn't see that you're in a 300l, how much is the add back and how often?

hey sorry i have 80g/300L tank. i fill with about 50gal of solution. when i top up i put in about 5 gals of RO brings me down to 270 ppm after 2 days its up to 300ppm . im 1.5years in using flood tables . im still learning lol . what am i doing wrong ?

I don't know flood tables but this sounds like heat. Either the lights are too close or the room is too hot, the plant is just sweating like a mofo trying to live, she is picking up water and just sweating it out. This leaves more nutrients untaken then water, presto your results. I can't think of another reason.

word

how can i flush them ? is it normal for the ppm to drift up slowly ?i dont know what to do . as for now they are getting RO at 50ppm . what shold i do anyone plz?

mine were doing this in veg but it seems liked 3days after the res changes everything would start to level out. i have alot smaller res. only running 6gals. i thought it was normal. i just planned or it by starting lower and letting it creep up to waht PPM i was shooting for. not sure that this is correct but its what i did to combat the problem.

ya i just woke up . they just had 12hrs on . fed x3 with Ph'd RO @40ppm . woke up and ph is fine but now the res is at 80 ppm . i guess the plants all took a piss nd shit . thats my flush ! im going to put in the nutes . starting at 400 ppm . they look almost 2 feet . hope im doing this right