Grow Mediums Ec ppm. Help

[12gauge]

Ok I've been reading and researching hydro. Something still is baffing me. The adding water back to the rez and making sure ferts are in proper range between rez renews. How do you keep your rez consistent with ppms and ec. I read if you have a 50 gal rez keep track of how many gals you replace until you get to 50 percent then run the remaining 50 without adding new water then clean and refill. How much does ec drift and how do you keep it in range between fresh start to dump and clean. I hope this makes sense. I want to step up my game if someone can point me in the right direction I'd be so grateful. Thank you in advanced. I understand I'd need to use ec and ppm pens.

 

[puggle6]

Really difficult one bro!

It's something you need to really read in between your res changes.

I think there is a chart around but it's not a full solution. Much will hinge on your own schedule, evap, temps/RH and plant uptake!

If all things considered are stable such as temp/RH and Rez temp and air exchange then you can start to map what's really going on

So, if everything is stable and happy and you see EC shift up or down then getting a handle on what is going on can be rationalized by how much your Rez level has changed.

Over maybe 3 days you should be able to work out roughly how much is uptake of nutes, uptake and expiration of water and how much is evap.

There is no real way to tell and things will shift as your plants build a canopy and take up more and expire more to evap vs how much food they are actually taking up!

There are lots of ways to manage whether it is taking half nutes out and topping back up to desired EC or depending on the swing just topping up with water and doing a regular full change.

Your plants will tell you if you know what to look for.

Best bet for beginners is to maintain a safe range maybe over a 7 day period with plain water top ups and then do half tank changes of fresh nutes.

Others hopefully can also offer insight!


f6

 

[12gauge]

Really difficult one bro!

It's something you need to really read in between your res changes.

I think there is a chart around but it's not a full solution. Much will hinge on your own schedule, evap, temps/RH and plant uptake!

If all things considered are stable such as temp/RH and Rez temp and air exchange then you can start to map what's really going on

So, if everything is stable and happy and you see EC shift up or down then getting a handle on what is going on can be rationalized by how much your Rez level has changed.

Over maybe 3 days you should be able to work out roughly how much is uptake of nutes, uptake and expiration of water and how much is evap.

There is no real way to tell and things will shift as your plants build a canopy and take up more and expire more to evap vs how much food they are actually taking up!

There are lots of ways to manage whether it is taking half nutes out and topping back up to desired EC or depending on the swing just topping up with water and doing a regular full change.

Your plants will tell you if you know what to look for.

Best bet for beginners is to maintain a safe range maybe over a 7 day period with plain water top ups and then do half tank changes of fresh nutes.

Others hopefully can also offer insight!


f6

It does thank you

 

[puggle6]

A bit more..

In my opinion, for autos is do not change full nutes to often. If you can maintain with half changes, top ups be it plain water, regular nutes or even shots of your chosen enhancers and keep EC within a range you are comfortable with for as long as possible.

Very close observation I have done is that my plants will stall slightly with each full nutes change.

I should say that stretching your Rez changes may not be right for you! It will depend a lot on your nutes and schedule!

6cents

 

[Simplicio]

Here's what I think is the best approach, and it has worked well for me.
1. Make sure you know how many gallons are in the reservoir at all times.
2. When checking the reservoir, decide on ppm and pH that you want, and add the right amount of water, fertilizer, and pH up/dn to achieve that.
For example, I'm using Greenleaf Megacrop, and I know that 1 g will produce ppm = 128 when added to 1 gal.
If my 30 gal res were 1.5 gal low at 390 ppm, and I wanted it to be 400 ppm, then I do this calculation:
ppm to be added = 10*28.5 + 1.5*400 = 885 ppm
MC to be added = 885/128 = 6.9 g
I put a small jar of MC on a scale, and remove enough with a measuring spoon until the scale reads - 6.9 g.
How much pH up/dn to be added is learned thru experience.

As far as res changes are concerned, I do partial changes to make sure there are micronutrients in the res.
Every day I empty out about 10% of the res, and replace it with fresh nutes as described above.
I've heard of some people never emptying theirs.

 

[EvilScotsman]

Hmm. ... a 50 gal res you say. I'm guessing your new to this otherwise you wouldn't be asking so my advice would be. ...
A full grown 1 pound plant needs 3-4 gallons per day so unless you've got 2000w above the canopy and an army of monster plants it'll still be pretty full after 10-14 days which is the longest I'd recommend going between changes. So you most likely won't have to top it up. Open yourself up to a lot of possible issues if you leave it longer. Especially if you aren't controlling the temps well.
Plants don't need much nuts in hydro. Requirements are roughly 100ppm per week of veg not including your tap water. So first 2 weeks they don't need more than 200ppm. Next couple weeks 400ppm. Next couple weeks it's 600ppm. Roughly, you've still gotta judge it as every grow is different.

If the ppm is rising then the mix is getting stronger. In which case you add water until it starts dropping. Then use those numbers to work out what the magic ppm number is to keep it stable.
If you can keep the ppm stable or just dropping slightly you'll never get any issues.

Regular changes means you know exactly what the make up of the mix is and its properly balanced. If you dont keep it balanced and you end up with problems its very hard for people to help you. Because if you don't change it then toxicities in the plant might actually be a deficiency in a certain nutrient and vice versa. Some people do get away with not changing for the full grow, I'm not saying it can't be done but for a beginner it's very inadvisable.
Keep the feeds weak and up it if bits of the plant turn yellow. Toxing a plant causes serious, sometimes irreversible damage. Plants getting a bit hungry causes almost zero damage.
Hope that's helpful buddy