Learned a lesson today that I'm sure the veterans already know. Filter socks may not be full, but that doesn't mean they aren't clogged! After work I got home and as always the 1st thing I did when I got home was look at my tank and the beautiful frags I have in it and I noticed my water level was almost overflowing onto my hard wood floors. I checked my ATO and found it almost empty. I started dosing Kalk a week ago, so I was worried that my PH and other parameters were high. So the 1st thing I did was check my parameters and thankfully they were not high. As of right now I'm only using a half teaspoon of Kalk per gal of RO/DI water and it only dumped 4 gals of ATO water. my PH was only 8.4, a tick high, but manageable. So I still changed as much water as I had left over from the weekend water change, which was about 8 gals, not much but still made me feel better. Then I checked to see what happened and this is were the filter socks come into play. I noticed that 1 filter sock was overflowing into the 2nd over the weekend but didn't think much of it because I have been periodically checking them and found no debris in them, BAD MISTAKE!!! the linings still clogged up and as a result caused the water to flow out of the overflow into the skimmer compartment. This may not sound like an issue but it slowed down the return flow and caused my return pump to pump out the water in the return compartment. My Tunze Osmolater sensor sensed that and started to add water, and kept adding water until roughly 4 gals dumped into the return compartment. Thankfully I found this and learned a valuable lesson, DON'T BE LAZY, stay ahead of the game and clean the filter socks before they think of becoming an issue. LESSON LEARNED!!! Everything is going good again and frags are looking awesome.