gogreen

being new to aeroponic's, I was wondering if and when to flush and discontinue nutes.

my ladies are going into six weeks now with red hairs beginning to appear. I have read about flushing and discontinuing nutes a couple of weeks prior to harvest. Can some one confirm or deny this and suggest an appropriate time frame or indicator?

HydroSan

Hi gogreen, welcome to HC.com

you may find this thread gets moved to the hydro/aero fourm by a friendly mod as we like to keep things in their place around here so newbies can find info easier

As opposed to flushing with fresh water, we're moving towards more of a leeching effect. That is, flushing with 400ppm nutes instead of fresh water. some poeple say leech for the last two weeks some say the last week to improve flavor, but it's all a bit hit and miss unless you know the genetics and when they normally finish.

The weekly flush, or flush by top up volume is when you've topped up the tank with it's total volume, it's time for the flush. 12 - 24 hours is enough to wash the plant wastes and salts from the system/rootzone, again we're using, Ph adjusted, 400ppm nutes for this as it causes less of a negative impact in the rootzone. the trick is to get into a routine and stick to it, flushing/leeching weekly is a good routine

Sanster

gogreen

much obliged Sanster! information useful it is - so if leeaching is once a week, due i maintain a normal regiment of nutrients during the rest of the time

HydroSan

yes mate, thats right. It doesn't matter weather you are in veg or flowering stage, the weekly flush is to remove salt biuldup in the solution/medium and remove wastes from the rootzone. Deviant explains what happens in the TDS link in my sig. It's a bit of a guess which nutrients the plants have actually used up (the only way to tell acuratly is to send plant matter to a lab and compare nute concentrations). The plant can also evaporate water from the res faster than it uses nutes, this is how the solution becomes too concentrated and becomes toxic.

By flushing with 400ppm nutes, and doing another nute change afterwards, to the desired level for your stage of growth, you are stressing the root system less than you would be if you used plain old water(somthing to do with ions exchange in the rootzone). Canging nutes removes the uncertainty of what is making up your nute solution after the plant used only some of the nutes you are replacing during top ups. Removing waste material and preventing salt biuldup is a weekly affair, a new nute solution is a useful side effect

Have a read of the hydro links in my sig for advanced insight

Sanster