question about perlite culture

[mdomingz]

hey everyone...

I see pictures all over (hydroponics, semi-hydro, perlite)... and all of them are in clear or white pots and everything looks pristine.

I recently put a dendobrium in all perlite in a clear pot....within a week it was all green due to algae. I'm wondering if the algae has a negative effect on the roots or if it is ok.... anyway i covered the outer side in tin foil to kill it all.

Any advice would be appreciated... if the algae-lite is ok.. i'll remove the foil... and if not...i'll replace the pot...

Anyway.. the final idea of all this is that i'm planning to move everything to perlite....

thanks everyone,
manuel,
panama

[E-Jag]

I don't believe that algae has any harmful effects on orchids, It is pretty much benign. If it bothers you, pull the plant out and soak the pot in a diluted solution of bleach and water for awhile. Will clean it right up.

[Bolero]

I bought a plant during the conference which is completely in perlite. I will see if this happens. The development of algae is unsightly and perhaps would indicate it stays wet for to long on top? Not sure but will keep an eye out for it. With good airmovement drying out the top of the pot it should stop it developing......I would think.

[Pilot]

The algae is an unfortunate by-product to moisture, light and importantly, fertilizer-- especially high phos (ever hear of algae blooms?). It has no negative effects on roots and is just unsightly, if it bugs you.

Once you pot a plant up in semi-hydro-- periodic use of physan 20 can keep it at bay.

[Bolero]

Interestingly, a tomato farmer who I am friends with turned up to the orchid conference today. He grows his tomatoes in Hydroponic conditions. The interesting part is that he says that the perlite doesn't hold much moisture and that's why they don't use it. So perhaps an alternative media is a better idea.

I am going to test how it goes with this standard cymbidium though, as the idea seems ok so far and there are some orchid growers who use it and nothing else.

[tansyflower]

You could always sit the clear pot in a tightish fitting opaque pot, and just pull it out when you want to check the roots.

I think somebody else suggested this in another thread.

[berniep]

G'Day Manuel

This is an interesting article on perlite GROWING ORCHIDS IN 100% PERLITE ---The Schundler Company
I don't use 100% but do mix it in my potting mix, as it lets the mix breathe as well holds moisture and doesn't degrade.

Cheers
Bernie

[Mick]

If you want get rid of algae, use a product called 'Alginox' (not sure if I spelt it right).
It is used for swimming pools and is available at stores such as K-mart. Use at 3ml per litre and spray on or soak the plant.

[Stelios]

Changing the clear pot to a brown/black plastic one will help. Dens do not necessarily need much light on their roots as some other genera so i guess your plant will be ok with less light on the roots.