Kratky fascinates me

I love the Kratky method especially for easily disposable fast growing short lived stuff like lettuce (1-2 month grow cycle).

Other methods like your ebb and flow is better for high value crops like chilis and weed imo :)

Do you have trouble with algae in the glass containers?

With clear glass, which I used in the beginning, definitely yes.
With green/ amber ones nope, or at least only veeery weakly.

Currently I try spray coating a few ones with white pigment, and see how it turns out with heating up in the sun and algae compared to the uncoated brown ones.

I've done a fair bit of kratky and dwc. Typically you avoid algae and other root rot issues with opaque containers.

You can order plant wicks like this. Very cheap. I find that they are more useful for watering potted plants in soil, but they've got all kinds of uses.

Polyester

Correct! 👍 I haven't observed much algae growth yet.

But I'm also experimenting atm how it turns out when I spray coat them.

This year I have a 50% shade cloth, but last year they were uncovered and hot afternoon sun fully blasted onto them, cooking everything to mush.

I now painted a few of them white, and I hope this reduces algae growth and heating significantly.

Sure, but for short lived, disposable stuff like leafy greens or herbs it's perfect! There's basically zero cost, and it's totally passive. You also don't need to wash/ waste any growing medium.

But for other more high value stuff, like weed or chillis, I use other, more sophisticated methods.