hi guys thanks in advance for all the support...
ok here goes.....
i have a 4'x8' aeroponic unit with a 125litre reservoir.
All is fine, now at week 5 of flower and looking real good.
Concerning ppm's, i have read in a few articles stating that aeroponics prefer a lower ppm of around 700 in veg and 900 in flower.i have looked through the forum and you seem to always suggest to follow the recipe for succes in aero.....
However, in the last mix, i tried the full mix (flower stage2) which says 1500ppm or so...I got the ppm reading at that level for about 115 ltres of solution.After about 3 days the solution was at around 85 litres and the ppm had risen to 1800.
My question is as follows: if I get the ideal nute ratio, shouldn't it stay at the same level, the water and nutes being use at the same proportion? In the first few weeks when i started, i used half the amount and the ppm's were actually going down.
In your first example where the PPM's went down, your plants were using more nutrients than water, whereas in your second example where the PPM's went up your plants are using more water than nutrients. (Evaporation may also be a cause of PPM increase). Nonetheless, this is normal and OK as Willard points out plants will use varying amounts of both water and nutrients at different stages of growth. If it gets too strong (your second example) you can always dilute the solution; similarly, if it gets to weak you can always add nutrients, change your reservoir more often, or get a bigger reservoir.
Thanks for your question and continued support.