Help, please: terminology re calcium supplements

I'm making my own container soil for growing tomatoes (this is my first year: containers & tomatoes), I'm following advice from one person, who's made several videos over the years, covering from seed start to harvesting, but my problem is that he uses different words for the available calcium source.

Pelleted Lime, pulverized limestone, agricultural lime, gypsum. . . I'[m so confused! Are these all synonymns for the same thing?? Or are they slightly different, depending on WHEN to use it?? For instance, a slurry of pelleted limestone is recommended at flowering and/or to prevent any further BER. . . but ag. lime )which he says is same as pulverized limestone) needs to be IN the container soil -and on another video, he says use pelleted limestone as the calcium source IN the container soil.

I'm following U of Fl container soil recipe: with added modifications specific for tomatoes. Equal parts of Miracle-Gro potting mix, compost, peat moss and vermiculite: with added modifications - one handful each of (calcium source once the above list is made clearer) and a slow release fertilizer (10-10-10 or 12-12-12) plus 3=4 chemically processed eggshells (processing leads to Ca++ + h2O + CO2).

Some help/advice would be greatly appreciated.

Limestone is calcium carbonate (Ca CO3) It is available in ground or pelleted form. Only difference is that pelleted form is cleaner to handle. Agricultural lime is usually also calcium carbonate. Gysum is Calcium sulphate (Ca S04 ) Primarily used to condition clay soils. also the main ingredient in drywall etc. The main reason for using lime is to raise the Ph of soil. Sometimes you will find air slacked ime which is Ca (0H)2. This can be a very fast neutralizer but is capable of giving caustic burns if you get it on you. Be sure to wear eye protection if you are tempted to use it. Lots of garden centers carry dolomitic lime stone which is Calcium magnesium carbonate CaMg (C03)2. Useful if you also need magnesium. All of it is ground rock except the Calcium hydroxide which is processed by first converting limestone to Calcium Oxide and the converting it to Calcium hydoxide.

MUCH thanks for your prompt, clear explanation!

So I'll stick to pelleted lime, since I'm using Epsom salts for Mg and S.

I've read that tomatoes prefer a slightly acidic soil/mix to grow in. . . and I think peat moss affects soil pH (raises??? lowers???) So would the purpose of adding a handful of pelleted lime to my 5-gallson containers. . . RAISE the pH toward what tomatoes prefer??

SHOULD I add pelleted lime, in your opinion??

I don't know. I only use lime to adjust pH and I know the Ph before amending, but I don't do container gardening. Peat moss can be acidic so the mix instructions probably include lime to counter the acidity. Tomatoes are pretty tolerant of fairly wide pH range.

As you mi9ght have guessed, I'm a beginner gqardening, so this will be my first attempt at container gardening and. . . just about EVERYTHI(NG to do with gardening is my first time!!

My area is extremely alkaline, to the point that none of the stores sell any type of lime products, but I grow great tomatoes. Like Farmerdill said tomatoes are pretty tolerant of a wide pH range. I purchase all my potting soil, I've seen many recipes that call for lime or other things that are not needed everywhere. I'm also on a well so my water is alkaline too, I just can't get away from it lol, but I manage to grow a decent garden every year.

Bet: As a beginner it is always best to follow the instructions if they come from a reliable source. U of Florida is a good source. As you get more experience you can tinker with it to optimize.