Is it time to start cal/mag??

[RetiredGuy]

Hi,

My White Widow autos have been successfully transplanted. I will be growing in both 5 gal and 3 gal pots and it will be interesting to see if there is much difference. These plants are about 2 1/2 weeks from germination.

I use RO water due to having very hard tap water. Last grow I ran into some deficiencies which I expect was due to not starting cal mag soon enough. I adjust pH before watering and will monitor runoff pH once I start to water to run off.

I am in 50/50 happy frog/ocean forest soil with 30% added perlite. According to FOX FARM this soil should not require nutes to about the 3rd week of growth. I think this is too long to wait for cal mag and am inclined to add it at the next watering.

I would love to hear what you fellow growers with more experience think.

Thanks and happy growing!

[OldManGrower]

My opinion and this is only my opinion is that I introduce cal-mag early. For plants the size of the ones in your pics, I use a four ounce squeeze bottle for watering. I use two or three drops of cal-mag along with ph-adjusted water. I don't think it will hurt anything and and it may help.

[dilvish]

those soils should contain enough for 3-4 weeks. beyond that Cal Mag is optional but in the case of your water, I'd add maybe an 1/8 of a teaspoon every other watering and just keep an eye on them..

[MH47]

Deleted by user

[Going2fast]

Using fabric bags I think you went a little heavy on the perlite. Don't feed them anything for at least another week. That soil has everything they need for awhile. No offense but for 18 days they are already stunted. I'm not a fan of transplanting autos. Too much can go wrong.

[RetiredGuy]

Same amount of perlite as the last grow, which is the amount recommended on the main site. Any negatives of a little too much besides cost?

[RetiredGuy]

Going2fast, I do not believe the plants were stunted by transplanting as they never missed a beat. Looking at your post on your grow, I agree my plants are smaller than yours at the same age. I also see we are using the same light.

My plants were under 2 T5 fluorescents for the first 2 weeks and were just moved under the SP3000 earlier this week. I started at 40% level and have increased the light to 55% now. Perhaps they would have grown faster if I used more light from the beginning?

[MagicMike66]

I use 1ml cal mag per litre of water. Your medium also looks a bit too wet for the size of the plants. When they’re that size, I tend to just water around the centre of the pot, that way you won’t drown the roots

[Going2fast]

It's possible. I start at 40% at 24 " away and it's cranked up to 100 by week 3. Could be the strain. I do love the light.

[RetiredGuy]

Thanks, got mine at 70% now and will be at 100 in a few days.