If perlite is yellowing, mix is too wet for too long. At 60/40 mix (perlite/soil), it should drain better. So maybe you should ditch that soil...(don't take it literally, but it doesn't sound good enough). Did you see the ingredients list by any chance? It could have too much peat and/or 'forest product' (whatever that is :) in it. Many ppl use 50/50 mix and report good results.

You could make mix of perlite, grit and some turface (if you have it) or small bark...or just perlite and grit, or even turface and grit. But you would have to test proportions of different substrates. I wouldn't think turface and bark alone are best as both will hold some water - could be too wet.

What brand of C&S soil do you have? I do the same method, but I sift the C&S soil first.

Hi, Lois. I have problems using any mix that includes soil due to my high humidity and rainy summers. And I've had my fair share of yellow perlite! All of my plants are outdoors all year long and now planted in gritty mix with no soil component. So I have a couple of questions.

Are your plants indoors or outdoors now? Will they be going out for the summer? And does your pot have a drainage hole(s)? I'm sure you already know that drainage holes are a must. Maybe humidity is causing you problems? And perhaps your pot isn't helping. By that I mean that some plastic or glazed pots don't allow evaporation like a terra cotta pot will. And double potting, using a cache pot, can work against you, too.

Just some thoughts!