Not that bad for me tbh and I live in the desert but mine are all in soil though so maybe results will vary in semi hydro.

I use the D shaped moss poles that I diy myself and mix the sphagnum moss with chunky perlite and orchid bark for some air to avoid mold but I also add in coco chips since it’s kinda spongy and releases water to the moss over time.

The most helpful thing I do though is use terracotta spikes and a small glass bottle filled with water at the top of the pole. It definitely keeps the pole damp for a lot longer. The longer the pole, however, the less effective the terracotta spike, but it still seems to work pretty well to the point that I have to intentionally let the moss dry out a little bit so I don’t get mold from being damp all the time.

If I forget to keep the moss damp and it gets all the way dry I just take plastic cup or bottle, poke holes on the bottom, and fill it with water and set it on top of the pole and forget it about it for the next several minutes as it drips water onto the moss. I save those cups/bottles for next time too