As part of my potting mix for succulents I have been using coco coir along with topsoil/compost, sand and perlite. What is a good type of coco coir to use? Is Canna natural (with a very light buffering) ok as it is being mixed compost or is Canna professional plus (which has had a full buffering) best?

I don't know what this buffering they mention is, but the cocofiber I use (25% of my mix) is pretty ordinary looking. I rehydrate it with pH adjusted tap water (pH=6), and our tap water is full of dissolved minerals, so I would imagine this might have the effect of buffering it. I also water with pH adjusted tap water so it's not like there is any shortage of Ca or Mg in the mix. The important thing is that the fiber has been (pre)rinsed free of salt, which any product designed for horticulture should be.

Baja_Costero said:I don't know what this buffering they mention is, but the cocofiber I use (25% of my mix) is pretty ordinary looking. I rehydrate it with pH adjusted tap water (pH=6), and our tap water is full of dissolved minerals, so I would imagine this might have the effect of buffering it. I also water with pH adjusted tap water so it's not like there is any shortage of Ca or Mg in the mix. The important thing is that the fiber has been (pre)rinsed free of salt, which any product designed for horticulture should be.

Thank you for your help. The coco coir I originally used didn't mention buffering so I hadn't thought about it before. It worked well for the plants but now the seller isn't stocking it anymore I'm having to look for an alternative. I wasn't sure what was best for succulents as some were mentioning buffering. I read that salt can be an issue - this brand mentions washing the coco coir in fresh water whereas with other brands it wasn't clear if this was done or if it may contain salts. What do you use to adjust your tap water pH?

I think the buffering thing is only relevant if you water with (RO) purified water, otherwise your tap water probably has enough minerals in it to make buffering irrelevant. There are theoretically some brands of coir that still have salt in them, presumably to save a step in manufacturing, but I don't know what reputable nursery would stock them. Any product for horticultural use should be prerinsed.

To acidify my water I use a product called "Acid Buffer" (Seachem brand) which is bisulfate with Mg/Ca as the cation. You can use a wide variety of acids for this purpose (some of them available as pool chemicals, others like mine sold "for planted aquaria")... the important thing is that the acid be free of sodium and ideally it should have minimal bioactivity (like the sulfate produced by mine). Some people use household (cane) vinegar. Whatever works for you, just be sure you test the pH of your water afterwards so you know you didn't overshoot. Adding acid without measuring the pH is a bad idea, at least until you know precisely how much to add.