Well I use an aggregate medium and I certainly don't experience 4 seasons.

From what I read, some (not all) volcanic soils are very water retentive; and also many different minerals. S0 some may not be so great for plants - but many are very fertile?
Most of us would leave out sand (if fine), and cocopeat & peat moss - at least most of it.

Pumice is good, sand only if large grains...your mix of crushed granite, bark & Leca may be good except how large are the Leca balls? Good mix would have particles of very similar size.

thanks Rina. I managed to get LECA balls of the same size as my granite and bark, approx 5-6mm.

strangely, the "experts" were recommending sand to fill in the gaps between larger particles, but I understand that the air space is important.

any idea if I MUST remove all traces of soil before repotting into gritty mix?

Probably not absolute must, while very much preferable. Is it difficult to remove because it's a hardened peat? That's very much a reason peat is not so great - it is either very wet & 'soupy', or if not constantly wetted it will harden & is almost impossible to re-wet. You can try to immerse root ball into water & let it sit to soften it (plant won't die if in water for a while. Peat can be re-wetted easier with warm water, hotter it is better. But not good for plants!!!). Maybe you can snap a photo of the root ball?

BTW, not sure if you mentioned what plants/succulents you have?

They generally don't care for too much humidity, so if you can eliminate anything you can control, they will cope better with what you can't change. Even small fan may help to circulate air.

Rina

Yes, remove as much soil as possible.

The yellowing lower leaves could be simple transplant shock, could be related to over or underwatering, or could be an indicator that the plants are in need of nutrients.

Josh

Rina, I have echeverias, jade, sedums and semps. Most of them were in terribly peaty soil or clayey soils that cracked when dry when I got them. I don't have photos of the root ball as they're all in the gritty mix now. I just hope I didn't damage the roots too much.

I'll be looking to get new succulents in the future but they all come in crappy soil, so just asking for future references. I'll snap some photos next time!

I've a ceiling fan going on, and air conditioning at night (they do need cooler nights right?)

Josh, I hope it's transplant shock. I'm looking at fertilising them, do you think I can do it now? It's about 2 weeks since I repotted them, or would it better to let them settle down first and fertilise later?

I'm currently watering them with rain water instead of tap water

Chris, how consistent? I'm watering them twice a week, so how often to fertilize a good start?

The best practice is to fertilize them every time you water. If you're hand watering, it's pretty easy to just dump a measure of fertilizer into your watering can, and doing this each time provides a constant source of nutrients. This is what I do during the growing season.

-Chris

Hi Chris, got it! Is there such a thing as over-fertilizing?

^ Yes. Too much fertilizer at one time can burn the roots, and not properly watering, by not flushing, can cause build up of salts. I'm a gritty mix user. I use fertilizer 1/4 to 1/2 strength, about every other time I water.

Rob

Like Rob said, too much fertilizer at once can damage plants. If the concentration of dissolved solids in the soil solution exceeds the concentration within the roots, the osmotic flow of water into the roots can be reversed, causing the roots to lose water rather than absorb it. This is called plasmolysis, or root burn. But as long as the concentration is appropriate, plants cannot be harmed by frequency of fertilizing. If you want, you can start with a reduced strength like Rob suggested. That may be best for indoor plants. Most outdoor succulents in full growth appreciate a surprising amount of water and fertilizer. They can almost be grown like tropicals. I normally use 80ppm N (~2/3 of full strength), but plan on bumping it up to full strength at every watering this summer.

Here's a good calculator if you want to determine the actual concentration of your fertilizer mixture.

-Chris