Gee, I am wondering. I have a shelf stable calcium solution that I made from vinegar, eggshells and cuttlefish bones. Do you think I should give my plants a bit of calcium in their first watering? Just for good measure or do you think they are looking good to go.
I'm not an auto grower so I don't know if auto's are calcium pigs or not, but if the surface of your pot gets crusty when it dries, and you crumble the crust up really well and then after it dries again from the next watering it's crusty again, it's likely that you need calcium.
The 1st crusting after the 1st waterings always happens so pay no attention to that, it's if it crusts every time it dries out that you are looking for. That indicates that magnesium is getting higher in the calcium to magnesium ratio, which means calcium is actually getting lower.
That being said, if you are only mixing the calcium solution to about 50ppm you can use it pretty much every watering if you like.
I follow the soil surface and I also use a refractometer to monitor calcium, but lots of people use low dose CalMag at every watering and have no ill effects.
I have tried that a few times just to see and if you keep it low dose (50ppm) I have never seen it cause harm, other than leaving calcium residue on the cloth pots after the grow is over, but a rinse in a CLR solution and then thru the washing machine without soap cleans that up pretty well.
Q2, I am not ready to water the plants yet. The bases of the pots are still damp to the touch. They usually start showing sex anytime from about 3 weeks onwards. They already have a layer of EWC on top. Do you think now is a good time to add the top dress (the
Elemental Blend we spoke about earlier)?
I do actually. I find top dressing works best if you put it and EWC on together, scratch it into the top inch of the soil really well so it's all mixed up and even.
The life in the EWC goes to work on it immediately and it waters in better, otherwise quite often it repels water very similar to how chocolate milk powder does.
Top dressing is something you want to be ahead on, not playing catch-up on.
I top dress every Wednesday from 1st uppot or from about week 3 onward if I sprout in big pots.
You don't want a thick layer though, you want the recommended amount sprinkled evenly over the surface, then a layer of ewc just deep enough to cover it, so maybe a quarter inch deep and even across the pot, and then mix it all in with your fingers really well, again checking for crusting, and then gently water it in.
Too much EWC at once will clog the top of the pots.
After applying EWC the surface will always crust up on 1st drydown, thats normal, but if it crusts every drydown even when you haven't applied EWC, thats low calcium starting.
Here is my formula I use for top dressing the blends.
(pot size in gallons) x3 divided by 4= weekly application rate in tablespoons.
So on a 5gal pot it would be (5x3)÷4, so 15÷4 which equals 3.75tbsp per week.
So 3.75 tbbsp sprinkled evenly over the surface with EWC on top, all worked in evenly, and then gently watered.
That is based on most mixes recommending 3tbsp per gallon of soil when adding it to the mix, and it lasts for about 4 weeks, so 3tbsp per gallon per month divided into 4 weekly doses, which is 3/4 of a tbsp per gallon per week.
Round it up and it's 4 tbsp per week.
My Gaia Green mix is very similar to your Elemental Blend for ingredients so it should be very similar in application.
I use Gaia Green Power Bloom if you wish to compare.