I was hoping someone might have some ideas to help me resolve an issue with growing media. Several months ago, I began growing 4 Nepenthes in 100% perlite hydroponically. The plants are watered 3 times a day for 15 min. each (the minimum time interval on my timer) with nutrient solution. They also sit in about 1" of water at all times (these are 1 gal. size nursery pots).
Each of the pots has 2 water delivery points, where irrigation tubing pours water onto the medium. Perlite has some wicking capability, but I don't think it's enough to distribute water evenly in the upper third to half of the pot, given that water is entering the perlite at only 2 points. To help distribute the water better, I cut sheets of cellulose sponge into semi-circles and placed them on the surface of the pots. When the water from the tubing flowed onto the sponges, they became saturated and started to transfer water to the perlite over the entire bottom surface of the sponge. This provided better water distribution than simply allowing the tubes to pour water onto the perlite directly.
However, cellulose sponge quickly rots when exposed to constant moisture and nutrient solution. So I am looking for a replacement. I bought a polyurethane sponge, but it doesn't seem to wick water throughout the sponge material very well (maybe I need a different kind of poly sponge?). I would like some kind of material that if cut into a 1" sheet or so, would become saturated fairly evenly if water were applied to it at only one point, much like a cellulose sponge.Ideally the substance would not break down easily or clog up the perlite below it.
Would anyone have any ideas?
BTW, 3 of the 4 plants I've tried growing this way are doing very well. The fourth, which was weak & had a smaller root system, died after I removed its rotting sponge. I don't think it was able to get enough water after that.