This is the cheapest source of perlite I have found in thailand, its still expensive but can be reused many times. 100 litre bags are a large amount.

http://www.higreenshop.com/category/399/วัสดุปลูกพืช-เพอร์ไลท์

Growing_carrots_hydroponically_using_per.pdf

Have you considered experimenting with biochar.

I think biochar has some great potential in soil use but for hydroponics you need a media that is inert. Way too much carbon in biochar that would cause problems.

Irecknoso, where did you look for perlite? Last time I got

somme at ACK in BKK out Suk/Oh Nut it was Bt.850 @100L bag

rice555

http://www.higreenshop.com/product/1995/เพอร์ไลต์-perlite-100-ลิตร-นำเข้าจากประเทศ-จีน

On 12/20/2019 at 3:59 PM, ireckonso said:

I think biochar has some great potential in soil use but for hydroponics you need a media that is inert. Way too much carbon in biochar that would cause problems.

What problems would the carbon cause?

19 hours ago, JungleBiker said:

What problems would the carbon cause?

Biochar has a good cation exchange.

In an hydroponic system it would hold onto the nitrogen , which would then would not be available to the plants.

What about Coco Coir

Plentiful and cheap here.