My simple solution https://www.leroymerlin.it/catalogo/set-pagliette-apex-maxi-pagliette-inox-cucina-metallo-35411852-p Or similar
Mine is loosing way too much; at one point i heard the water pump going insane and checked the level after a 40 km drive on the road and it was too little. I checked with ibeat and it was at 115 degrees celsius...i think i have a blown cylinder gasket imo. View: https://youtu.be/EHGwGC_YA-A
I wonder if I use RTV glue on that little hole and just seal it up, every time I do an endo it squirts lol. I like the metal mesh solution too, never thought of that.