How long to keep res/nute mix??

Hey there!
I have a 25 gal res nuted up and ready to go for a 12/12 cycle. This is in a GH AF20 w/diy res.
I had clones vegged and ready to go in two weeks ago---is why it's 'ready to go.' Well, change of circumstances costed me the clones and I now have another group ready to go in.
Should I dump the mix that's been in there for going on three weeks? I 've had the system running the whole time and there are plenty of bubbles keeping it mixed. The PH has dropped just over a point to 4.6 and the ppm has gone up a bit as was expected...there are no build ups in the lines or anywhere I can tell.....
It looks/smells good.......

Thoughts?

Thanks!
gman

im told 2 weeks then drop

Yeah about that maybe a little longer if its more stable. 4.6 is quite low, 5.0 is kind of the bottom end of what you should have. if you're using GH 3-parts don't pH adjust for 24 hrs because you'll end up over-adjusting. Throughout most of the plants life you will probably want to change the res at least once every 2 weeks if not once a week just to accomodate its growth through different stages.

dbo24242 said:

Yeah about that maybe a little longer if its more stable. 4.6 is quite low, 5.0 is kind of the bottom end of what you should have. if you're using GH 3-parts don't pH adjust for 24 hrs because you'll end up over-adjusting. Throughout most of the plants life you will probably want to change the res at least once every 2 weeks if not once a week just to accomodate its growth through different stages.

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I wish I was lucky enough to be able to change my nutrient solution that often, but every two weeks is where I'm at. My res is 70 gallons, is a BITCH to try and move around, drain, and clean, and it's filled to only about 50, so I can top it off with water as the plants suck the water from it after feeding and the nutrient concentration rises. I swear, I adjusted and topped off my nutrient solution just yesterday, and the plants have already taken almost-10 gallons from the res in just three feedings! (24 hours) Fuck, I wanted to take my motorcycle out for a few days and ride, but the way things are going, I'm trapped for a little while. Life could be worse I guess but damn..... And btw, I keep mine between 5.5ph and 6.3, and things are looking peachy.

Thanks you guys!
I always keep the PH at 5.8 when I am using the mix. I've always flushed/dumped at least every two weeks.
This mix I am referring to has not been used. It's been in the sealed res with two airstones going and the system running. I'll PH it correctly when/if I reuse it.

So, with nothing being used out of the nute mix(other than minimal evaporation<---why the ppm rises), what's going to make it go bad? I guess maybe that's what Iam asking. Has anybody witnessed or know why it would go bad??

Thanks!

I would def drop your old nute solution. And if you can change it once a week, especially in the mid to end stages of flower. there are things that are good to add such as MOAB towards the 6th or 7th week. Good luck with your new clones.

Lido said:

I would def drop your old nute solution. And if you can change it once a week, especially in the mid to end stages of flower. there are things that are good to add such as MOAB towards the 6th or 7th week. Good luck with your new clones.

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Thank you, Lido! Yeah, I am not going to take any chances and go out there and dump it before the clones go in tonight. It was just that I am trying a run with AN nutes and I had that greased up and ready to roll. I am quite sure it would be okay as those 1st cuts were only in there under 48 hours and everything is still squeaky clean, if you know what I mean.....but this is why I asked; haven't been here before and not going to take chances on this run(dont want to mess two in a row up, lol).

Thanks and + rep for all of you that gave me some feedback!

gman

Well especially if you see white salts and solids resting on the bottom of the reservoir that is a bad thing and the solids are solidifying rather than staying diluted. Also if light gets into your res you could grow some algae or other harmful micro organisms. If the plants are eating and eating for a long time they will eat too much and cause a deficiency if you don't adjust.