Fluval sump leaking ? Water level too low for heater/return pump.

[Nanolifeuk]

I removed my Intank chamber 1 basket to change chemi-pure bag. When I put the basket back in the tank, water levels have decreased in chambers 2 & 3.

It looks like water is trickling through the side of the basket rather than through it (see second pic)

Because my heater isn’t fully submerged the temperature in the tank is going up (27c on lowest setting) and I cannot run my ATO as the water level in the sump is constantly going up and down.

I have been sliding the basket up and down for hours to see if there’s a perfect position for it but I can’t get it back to normal. Please help !

 

[Jon's Reef]

If the heater is not fully submerged it may crack or explode.
Try removing the chemipure bag and reinserting the intank. If the water levels go to normal, the bag is blocking the flow too much.