DWC ...PPM build up . Not changing water enough ???

Hi Guys N Gals . Im having great success but due to the nature of my away from home work , I dont get the chance to replace the water in my set up during flower . Its has a float switch and constantly tops its self up with pre mixed nutes . I run between 1200 -1500ppm in the feeder reservoir and start with around 1000-1200ppm in the new flowering brew . My question is.... often when i get home after 4-6 weeks away the reading is up to 2000 - 2200ppm , is this a false reading due to residual build up , plants simply not picking up the nutes or some such shit .
Also heres a pic of my "cherry pie at near 8 weeks " , which is the suggested flowering time , do you think it should go much longer or not .

Tasman69 said:

Its has a float switch and constantly tops its self up with pre mixed nutes . I run between 1200 -1500ppm in the feeder reservoir and start with around 1000-1200ppm in the new flowering brew . My question is.... often when i get home after 4-6 weeks away the reading is up to 2000 - 2200ppm

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Reduce the strength of the nutrients in the top off res. Something around 50% strength would be the place to start.

Tasman69 said:

Also heres a pic of my "cherry pie at near 8 weeks " , which is the suggested flowering time , do you think it should go much longer or not .

Click to expand...

It does look close to done, watch the trichomes for signs of amber. I like to chop when I have mostly milky and cloudy with a little amber starting to show up.

Also, back off the nitrogen in late flower.

Thanks bro , appreciate the advice.

If you have to leave for 4-6 weeks at a time id get away from hydro until you can afford to automate ypur dosing of nutrients personally. Thats just too long to leave it alone in flower imo. Your yields are suffering big.
I use an auto top off barrel as well and am not able to leave it much more than 2 weeks without doing something with it.

Better make sure your air pumps are on an uninterruptable power source in case electricity goes out for more than a few hours; plants will drown otherwise.