OK Rkymtnman, it has been a couple of days since calibrating all 3 meters...and I guess it is true that you get what you pay for... The cheapie is the first to disagree...
This afternoon the GroChek read 5.8 when I got home from work, Hanna handheld read 5.8, my cheapie read 5.9.....first difference seen. But it was easily brought back into calibration.

Now I have a question.....regarding PPM. Over the holiday I dropped my PPM back down to about 1200-1210...and it seemed to stay there for a few days...until today! Last night at lights out PPM was right at 1200. Today at lunch PPM had jumped to 1290!!(about 13 hours) and noticed water was down some.(these girls are drinking about 3 gallons a day!)

So if my PPM is jumping up by 90 it says that they aren't eating what is being fed?? Or being fed too much? This is what I was thinking so I wanted to drop my PPM...and I figured if 1200 was too much I was going to aim for 1100... So I ph'd about 4 gallons and started slowly pouring it in...I went back 30 minutes later and it had settled at 1110.....

I guess my question is...is dropping PPM by 100 or so OK? Or is that a huge change?

And I guess second question is other than over feeding, what would cause my PPM to climb that much? It never has jumped like this before, unless I added something.

Everything else is looking good and holding steady. Today is day 35 of 12/12. This should be a little more than halfway!!

Happy

Hey Happy,

Yours are looking nicer than mine. I think I saved them but not the quantity I was hoping for.

Yep, I have seen this with my grows. As they get deeper into flower, they need less nutes. I would shoot for a number (maybe 1100 or maybe 1000). I think as long as your ppm's are dropping, all is OK. but going up is a sign to start to weaken the nutes.
so at 1100 now, if they go down then you are OK. if they go up, then try 1000.

but yeah, now you will get the feel of LF. the main mantra is "let the plants tell you what they need"

RKY

and my milwaukee mw101 pH meter is enroute. i'm going to do a quick flip and try 5 of the same strain in the same tub. thanks to SME and you, I am going to do drops and a meter. time to get serious.............

I wouldn't be fixated on the ppm so much but 100ppm out of 1200 isn't much especially if they're being over-fed. It could have been that the temps or humidity changed a bit or they might just be getting bigger or older. How many days are you letting it go before topping off and adjusting?

I do agree that the plants will tell you what they need. Were they showing signs of nute burn at 1200? If the plants still look good at 1100 then don't sweat it.

Congrats Rkymtnman!! I think you will like it... I too have intention of running the drops along side the meter...once the newness wears off the Hanna...lol

PPM settled at 1110 and was unchanged when the lights went out...so I will know around lunch tomorrow if I am closer to where they want to be.. They are showing more tip burn than I had been seeing, but it still not a lot. I have been topping off about every other day, which has me mixing 5-6 gallons.

And tonight, I went in to check everything & take some measurements before the lights went out...and when I went it it was noticeable warmer than it should have been!!! My one week old speed controller and fan were NOT running! I plugged the fan directly into an outlet and it cranked right up.. Next I tried the speed controller in another outlet...and nothing! Not even the power light! After trying it in different outlets, on different circuits, apparently my one week old speed controller has crapped out!! So fan will run full time until controller is replaced...I guess..better than having them bake.

If I had ordered a spare speed controller it never would have failed!!

I think you're still too obsessed. I'd go a week (or several once you get it tuned) and see what happens. At your current rate of consumption you should be able to go 3 weeks without topping off (with a 70 gal res) so lets work your way up to one and then two weeks and see what happens.

Since you are seeing a bit of burn it may be that 8/16 is too much for LED plants as rocky and I were talking about earlier. If you want to experiment, take 1 gal of water and add 7/14 and see what ppm you get. If it's 1100 or less use that instead of 8/16 for a while and see if the plants tolerate that strength. If 7/14 is over 1100 or they continue to show signs of burn try 6/12 and see what you get. The whole idea of LF is that you should be able to use it through the whole grow; you shouldn't have to constantly adjust a few ppm here or there.

How often are you draining, rinsing/cleaning and refilling the res from scratch?

The added heat from the bad controller could explain the extra water use and ppm climb. I think 7/14 or 6/12 might be better for LED than 8/16 though. You're right, if you had a spare controller the other wouldn't have died.

I drained, cleaned, flushed & refilled about 3 weeks ago when I switched over to Lucas Formula. I've done nothing but adjust water levels, top off and adjust ph since...

Also, it is my understanding that as the roots develop in an Aeroflo, you gradually lower the drain tubes in the chambers....which I have done. This reduces the overall volume of water. So instead of some top offs I have lowered the water level in chambers...figure my total volumue is about 40-45 gallons at this point..

Plus, the failure of the speed control was after I lowered the PPM... I will see in about 2 hours how much PPM has moved since last night...

SME, different topic... I prep for building a PVC frame to hang Orca panels on all 4 sides of my Aeroflo...

How much clearance should I allow between the plants and the panels?? I don't want to put too much space but don't want crowd them either...

I am thinking about like 8 inches from outside of grow chamber?? 3" from site center to edge + 8" would give me 11" out from base of plant...

Does this sound acceptable?

Happy

Well lights came on and I couldn't wait to check..(maybe I am obsessed)...and happy to see PPM held steady and is still sitting on 1110...no change!! Even verified reading with hand held....

I am Happy!

So, a frame that's 7x9-ish? Be sure not to glue it so you can adjust later, if needed...

Those lights will only cover so much space, when I checked the dimensions of the aeroflo60 it appears to be bigger than your lights will cover properly. The orca film will help a little but you may want to consider not using the outside chambers when you try your next setup.

You may also want to consider not topping off for a week and then doing a drain, rinse and refill at the 4 week mark just to be safe.