Does this ppm equation make sense??

One thing I don't want to do is mix nutrients up and add them to my bubble buckets whilst watching the EC meter do it's thing and then adding more small amounts until it's at the correct ppm level. It sounds tedious and long winded. I would prefer it if I knew exactly how much nutrient mix to add to the bucket right off the bat so I came up with this and I wanna run it past a few people to see if it made any sense.

Lets take 1 of the 5 gallon buckets for example.

I want my ppm to be 800. It's vegging and taking lots of the mix daily so I give it 140ml of nutrient mix (or however much i need to get it to 800ppm) so when it's done, it gives me roughly the readout I'm looking for at 1.6 on the EC meter.

Now 24 hours later, I take the new EC reading and noticed that it has drank a lot of the mix I gave it 24 hours earlier. The new EC reading say's 1.5. So in 24 hours, it's consumed 50ppm of nutrients.

Ok, so now I know how much it's drank, I'll top the water back up to it's original point and EC again. So let's say for example, it's now 80ppm's lighter than it was originally after a little more dilution. I'll mix my nutrients and then use the following equation to allow me to put in the exact (well maybe not exact but roughly) amount required to get me back to 800ppm.

I take the first reading of 800 ppm's and add the new reading of 720 ppm's = 1520
Divide by 2 (to get the average)
Times that by the amount of Nutrient mix used (140ml) 1520/2 x 140=106,400
Divided by the reading 24 hours earlier (800) 106,400/800=133
Then take that away from the nutrient mix from 24 hours earlier (140ml) 140-133=7

This should be the amount of mills I should add to the bucket to get it back to 800ppm's (7). I mean, these numbers are all just to work out the final amount of nutrient mix, I'm not saying that 140ml will make your water 800ppm. In theory, this equation could be used for more than just a bubble bucket couldn't it?

Does anybody else already do this?

Does this make sense to anyone or am I tripping after eating these cannabutter cookies?

you can either add back plain water or add back water+nutes. some peopele do the add back of nutes and never change the res for a whole grow if you do it right.

stop mixing ppm's and EC though. makes it easier. one or the other.

take 1 gal of water. mix x mL of nutes. what is your EC? if it's 0.8, then you need to add 2x next time to get 1.6 EC you can make a chart of what mL of nutes gives you what EC if you like and get as precise as you want

Your making it harder than what is has to be.

Carolina Dream'n said:

Your making it harder than what is has to be.

Click to expand...

That's what she told me

Am I though? I can do this little calculation within a couple of seconds, top up the bucket and syringe in the required nuts. Doesn't seem hard but hey, it's just a notion I was thinking about.

Explaining it was the difficult part lol