the water level is only to bottom/or just below bottom of netpots, bubbles pop...hydroton with root-powdered clone inside gets damp/wet and grows roots...you DO NOT want water all the way up to the point it would drown a moth...you want the plants to seek the moisture, promoting a strong root system...I used to use a single
fluoro tube for rooting, have since changed to cfl/250hps for clones/seedlings...