CAPCOM said:
It takes way way too long for the calcium from egg shells to be readily available for the plant to use and uptake.
The following will really help explain it far better than I ever could and add to what I have been attempting to explain. I am sold on this product line and this year you will see the results.
https://www.youtube.com/watch?v=HZg1KaWwIfs
https://www.youtube.com/watch?v=_BjbW2KPbTw
Nope, doesn't take too long, lots of organic growers use them without a calcium deficiency to prove it. Calcium carbonate sources like egg shells are
superior.
It's supposed to break down slow. Slow release continues to give plants calcium they need instead of an overdose then running out then overdose again, or the grower watering too much or it raining too much and money is washed out of the pot, or did you propose that a grower has to measure out a tiny bit and use it frequently, even every single day and time they water? What a huge burden that would be! Do it once at beginning of season, or end of prior season, and then forget about it.
If you don't have access to sources of calcium, sure you'll then have to pay for some special thing after that already in the soil is depleted, but don't for a second believe the marketing bullshit that egg shells don't work because I've been using them effectively for decades. That's how the industry works, they twist the truth implying that you NEED them, when the truth is, people were effectively growing plants, even nature by itself did, long before and long after they're around.
Now about what I wrote. Egg shells can even break down TOO FAST if the soil is too acidic. They should not be used exclusively to fix a severe/low pH because it could be a detrimental excess of calcium salts but the situation in this topic is only a small pH change which makes them ideal.
You don't even have to try to get a tiny particle size. I dump mine in an old plastic coffee container and stomp them down with a piece of 2x4 wood only enough to compact them and make room for the next wave of shells. They end up about half the size of a BB-gun, BB by the time the container is nearly full, except a larger particle size for the top layer. It is not theory that this works. It has worked for me for many years reusing the same soil in pots. I do add other compost to those pots, but the rest is very low calcium relative to egg shells.
Calcium is way too easy to come by to be spending money for it, IMO. You don't need to make anything in your soil a small particle size if you just calm down and give it time. Forget about a week from now and think this season about what your soil will be like NEXT season, or else you're forever chasing your own tail. However in the case of egg shells, even if you don't crush them, unlike say twigs, they are thin and have a large surface area even if left mostly whole.
The only reason I crush mine as much as I do is the practicality of storage space. They take up less than 1/20th the space when crushed and it's just a few seconds to do every time more are added, to break down the top you added and the bottom just compacts due to being at the bottom. There is no need to go to excessive measures to do what nature will do for you, unless you're just a glutton for punishment.
