Eshopps has a new probe holder that uses magnets to keep it in place. It is amazing to think that a magnet probe holder has just now come out for a sump, we have been getting by for years with suction cups and custom made sumps with probe holders built-in. But not any longer. The biggest feature besides the magnets that can be easily overlooked are the probe holders account for or hold calcium reactor tubing in place as well. No other probe holder on the market has that nifty feature. This allows you to keep your sump all tidy when working down in there and it gives you correct readings for the affluent coming from your reactor. Expect this to be available in the early summer for around $30 from Eshopps.