Question about RO + CalMag

[ShutUpDonny]

Hey all.

So I use RO water on my seedlings, but just read that this is actually too much of a good thing. Basically that RO filters out many micronutrients. That sure explains why several leaves on all of my seedlings are kinda stripey looking > CalMag deficiency.

Since there is chloramine in my town's water I want to keep using RO. So my question is can I use CaMg+ on my seedlings, and can I use it at label strength? Every time I water?

Thanks.

 

[Twelve12]

Do you have PPM meter? Add some CalMag+ and get it up to 50 PPM for seedling then work up to 200 PPM for mature plants. You would need to add this every time since RO contains nothing or under 5 PPM if any. Good luck!

 

[ShutUpDonny]

Thanks 12! I do, and oddly the RO PPM is around 50 already. Time to change the filters, I guess... Anyway, the girls are two weeks old, so I'll get right on that, and start supplementing like you suggest.
Biggups for the help!

 

[YardDog35]

Are you adding dolomite lime to the soil? That adds a lot of Cal/Mag to soil and also buffers PH. 1 cup per 1 cubic foot of soil. Takes some of the guess work out of it

 

[ShutUpDonny]

Yessir! Wish I'd read a little more before germinating the damn seeds. The one accidentally smart thing I did was plant them in 3x3 peat pots, so the girls will be moving on up in another week or so. I have a big bag of lime waiting for that to happen.

Will I still want to water with CalMag after that though?

 

[YardDog35]

Check the ingredients on your dolomite to make sure it has cal/mag in it. If it does that should support them at least through veg.

Youngsters don't really require too much Calcium and Magnesium though. Usually the deficiency shows up early in flower, or late in veg, if vegged for some time. I know you said your ppm is 50. Could it possibly be lack of nitrogen? Is it the lower leaves? They might just be hungry.

 

[ShutUpDonny]

Yep, it's in the lower leaves. I'll put up a few pix in a second. Man, the help is MUCH appreciated!

 

[ShutUpDonny]

Here goes:

So whaddaya think? I didn't want to give them nutes til they got a little bigger, but your description sounds spot on. At first the yellowing was more striped, but in the last 24hrs it's pretty much taken the bottom pair of leaves on almost every plant.

 

[YardDog35]

What type of soil are you using? How close is that 65 watt cfl?

 

[ShutUpDonny]

They're about 5" away from the lights (2 65w blue and 2 45w red).

The soil is about half potting soil, 30% perlite, the rest vermiculite and compost.

(Thanks for the quick responses!)

 

[Twelve12]

The plants needs more nitrogen it's eating itself away. What light photoperiod are you running?

 

[ShutUpDonny]

24 straight. Time to switch to veg, for the sake of nutes _and_ lighting?

 

[ShutUpDonny]

Well my timers should arrive tomorrow, so I guess I'll set up for 18/6 when they do. Thanks for all the help, folks!

 

[YardDog35]

The plants needs more nitrogen it's eating itself away. What light photoperiod are you running?

My thoughts exactly. They look really good. Nice size, and good looking new growth. Hit them with a little N. Start slow, your soil most likely has N in it as well. The one pic looks like a burn though, tips of the leaves are brown. If that persists it could be possible your soil is 'hot'. Add some food and see what happens, they'll be growing quickly so the food will be good.

Well my timers should arrive tomorrow, so I guess I'll set up for 18/6 when they do. Thanks for all the help, folks!

18/6 vs 24/0 is an endless debate, lol. Some swear by some darkness, but even Ed R. and other authors suggest 24/0 is best. Either way don't forget 36 hours of darkness before the 12/12 switch!

 

[ShutUpDonny]

Done and done! Man, mixing nutes to 1/4 strength is tough - ended up with 2 gallons worth before I had the ppm under 800 and the pH at 6.5 (had an ugly run-in with EJ pH up). I have it all in an open bucket with a bubbler now. About how long will they last?

Anyway, fingers X'ed. I'll keep a close eye on em, and will certainly report back when something changes. Again, thanks 100000000!

 

[Twelve12]

18/6 vs 24/0 is an endless debate, lol. Some swear by some darkness, but even Ed R. and other authors suggest 24/0 is best. Either way don't forget 36 hours of darkness before the 12/12 switch!

I respect the old school growers and their knowledge. However, through trail and experiments I've found that dark hours for plants provide healthier plants. And with the current experiment with the Gas Lantern Routine, it will put an end to the debate. Will have plenty of proofs. For those who still like to debate I say give it a go before continuing with the debate. Hehe

 

[Twelve12]

I have it all in an open bucket with a bubbler now. About how long will they last?

Best up to a week. Check the ph again before feeding the plants. With the bubbler going in the premix it will create high ph.

 

[ShutUpDonny]

Thx for the pointer about re-checking pH on old nutes. I'd like to think that I would have remembered to, but I know me better than that.

So what do you run for a light cycle, Twelve?

I have to say, as one who knows nothing and has done 0 research, that it makes sense that plants need a little dark time. If I need sleep then so does everyone else - plants are people too.

 

[Twelve12]

ShutUpDonny

• Not to get too much off topic here but I've been running an experiment with the Gas Lantern Routine in my perpetual grow. Check it out. Tomorrow is another update on this, completing it's 2nd week under the routine. Basically for veg I use 12on - 5.5off - 1on - 5.5off.

 

[ShutUpDonny]

Hey man, not at all off-topic as far as I'm concerned. I'm really curious about your technique. Going over to read it now...