Recirculating Growers How Do You Top Off?

Do you:

1. Top off the rez with fresh water, PH the rez and then dump the rez when you have added back the same volume as your rez?
   
2. Top off the rez with 1/2 nutes, PH the rez and then dump the rez when you have added back the same volume as your rez?
   
3. Don't top off at all, dump the rez just before it would make your pump run dry.
   
4. Other

What do you do and why do you feel it is the superior way?

I dump the rez every 14 days. I top of with full strenght,but i run low ec 1.2 or 600 ppm max.
The point is to synchronize plants diet.they shoul eat water and nutes in the balance.

When i made fresh rez. wit ec 1.2 and walk away ,after 2 days Will still be 1.2 ec in the rez.

I just refill with full strength solution. I believe that it is important to figure out how much water/nutes your plants need, and strike a balance with them.

I never had a ec/tds meter before, so I am looking forward to doing a little more scientific approach now that I am better equipped this go-around. I had discovered that when using RO water, with the 3 part Grow/Micro/Bloom that I never had to worry about PH. When mixed to the strength that the plants seemed to like, the PH would come out to a nice yellow, with no green tint. then as time would go on, and I would be refilling the res; I would find that the PH would rise. When it would get to a pale green, I would dump/flush/refill with fresh. It was my assumption that the plants were using up the nutes, faster than the water, causing the PH to rise, but that was only a guess. I did like the way the PH would slowly sweep across the range from around 5.5 to 6.5. I just hope that I don't get lost in the numbers/science, because I used to just fly by the seat of my pants, using the girls as my guide. Well that and a bit of PH indicator solution. It was funny though, because I could beat a lot of people that had all the meters, and ran a dozen different nutes. In case you haven't guessed, I'm a fan of the Flora G/M/B line (there is a reason it has been around, basically unchanged since the 70's) I love it how every new nute company that hits the market, bashes on Gen Hydro.... then a few years down the road, they make their own knock-off GMB line. If ya can't beat em..... LOL

Sorry, random babble

I change my res every 10 days. Helps to make sure they get fresh nutrients and helps to keep me on track with a day count.

Use a passive res and a float filled with full strength nutrients, it will keep your solution stable for long periods of time. I only change out nutes between veg and flower. And sometimes I go 2 weeks without seeing the grow, when I come back it's always at 800 ppm and close to 5.8 ph

Big greenhouses run by people with relevant degrees and doctorates have expensive machines to keep the EC and pH spot on 24/7

I do not know better than these people, so I copy them as "best practice"

The only answer I have not got, is do these places slightly vary the pH level to optimise nutrient pickup, some people on weed forums advocate it

I don't ever change out my res during a run. I don't really even do it between runs. Or check pH.
https://www.icmag.com/ic/showthread.php
Lots to learn here

Cm

Recirc is a roots-in system, handling it like a roots-in system will get you the best results. (any system where the roots are constantly exposed to nutrient solution)

No need to dump the res, no need to maintain a constant pH, properly maintaining the reservoir is very simple.

Mix up the res with r/o (or other 14ppm 7'ish clean water) and your nutrients, to within 50ppm or so of your target strength. Add pH up to reach a pH of 5.4. Top off daily with pure r/o, zero pH adjustment.

As your ppm drops, the pH will rise. When it hits 5.8, re-add nutrients back to initial ppm and your pH will be at 5.4 again. This rise should only take 7-10 days. If it takes longer, you have too much nutrient solution for your light, shorter and you don't have enough.

Rock solid predictable for me, for over 15 years now. BTW, I recommend using nutes and pH up only for the first few runs. Additives which alter pH must be used intelligently or they throw off this natural swing.

cravin morehead said:

I don't ever change out my res during a run. I don't really even do it between runs. Or check pH.
https://www.icmag.com/ic/showthread.php
Lots to learn here

Cm

Click to expand...

Your link doesnt work

how about now?

https://www.icmag.com/ic/showthread.php?t=23357

cm

I hand feed because in my opinion it grows the best cannabis available. Everything is fresh, the plants have unsaturated roots able to function precisely feeding every 4-7 minutes secreting what they need to without mucking up the whole garden from bad culture..

A plant that has no need to shut the caspian strip from solute or to metabolise organic protein will use 99% more ATP to process terpenes.


There is such a thing called luxury compensation to Agronomists.. You make no use of this with Hydroponics

I prefer topping off my res with fresh water, or a mild solution mixture as needed to keep the ppm's in the desired target range while keeping track of the amount of water/solution used to top of my res. For example; if I'm using a 30 gal res and I top of with 5 gals 6 times i know it's now time to change my res completely and renew a fresh mixture of solution. ( 5gal x 6refills = 30 gals) This is what works for me and makes the most sense when it comes to giving the girls what they're telling me they want/need.

cravin morehead said:

how about now?

https://www.icmag.com/ic/showthread.php?t=23357

cm

Click to expand...

Thanks this is awesome info

I'm just adding water to adjust the EC, no topping off. Changing nutrient solution when container is almost empty, about every 7-10 days. Also flushing the medium 2-3 times with water during a grow to wash away excessive nutrient salts.

The more res changes the better with water and nutrient waste being the mitigating factors imo. One top off max for us as you don't know what he npk values are regardless of EC once the plants are feeding.