Pure Perlite as growing medium

[Wort]

Hi, has anyone here tried Perlite as the sole ingredient of substrate for small terrestrial Utric's? I have given it a go in some little sealed starter colonies of U. Prehensilis and they seem to get by okay. I'm now thinking of trying it in my indoor Utricularia terrarium next year. Anyone have any experience with this method?

Cheers from Bill.

[Sedumzz]

I would avoid it pure, as perlite's texture sticks to water, making it anaerobic when lots of fine perlite is crowded together

[Wort]

Hi Sedumzz thanks for your reply.
I don't think this has occurred in my experimental colonies, but they are in very small containers. From what I remember from my Aquarium days, Anaerobic conditions generally occur in deep, fine substrate layers. Maybe the substrate is not deep enough for the oxygen to be depleted?
I will try further experiments with a deeper substrate to see if I can recreate the conditions you describe.
Thank you for your help.
Cheers from Bill.

[Wort]

Hi, the experiment has not created anaerobic areas yet, but I will keep things going for a few more weeks. However, my colonies in 1:1 Perlite and chopped Sphagnum seem to be pulling ahead in terms of growth. Therefore I am going to use this substrate next year.

Cheers from Bill.

[partisangardener]

Pure perlite has no organic matter to feed prey and beneficial fungi. That's maybe the reason for better growth in the mixture.. Perlite crumbles all the time if moved mechanically, so maybe if this dust accumulates anaerobic situations might occur, if some little organic matter from the plants feed it.

To feed anaerobic bacteria need elements like sulphur to get their energy, if no organic matter is available. I do not know what perlite offers in this respect.

[Tropfrog]

Anaerobic environment and anaerobic conditions is not the same thing. You can have the environment without the bacteria activity but not the other way around.