thanks for the welcome and reply. I dont fill it up all the way to avoid splashing out when water return through the siphon. I put in the hydroton and totally forgot it takes up space in the grow bed, duh! and the water level looks good now. However I was letting the system run, and my bell siphon just stopped working. It was fine with and without the hydroton, but when I came back it wasnt working. No blockages, what should I look for to fix it? How can it just stop working like that?