Leak from bottom of DE filter.

[Phillbo]

Hi all, I have a Nautilus FNS DE filter and have developed a small leak from the bottom of the filter. I can't see where the leak is coming from but the slab under the plastic base and the dirt for a few inches around the base are damp. I noticed this after I experienced a spike in pressure a couple days ago. Normal pressure for my system is 10psi with 15psi being my target backwash pressure. Something caused a spike the other day to about 24psi and I believe this may have contributed to the leak.

Is anyone familiar with the workings of this filter system to help me identify potential failure points at the bottom of the tank ? There is a pipe that runs under the tank and connects to the backwash valve so I assume there are connectors that may have o rings that could have been damaged by the pressure spike.

I plan to do my annual cleaning of the grids in a couple weeks and figured that would be the best time to pull the tank and fix the leak so any advice on what to look for or a rebuild kit for the connectors would be appreciated.
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[JasonLion]

You need to narrow down where the leak might be coming from. Water can run along the surface of the tank for some distance so watch for damp spots on the tank surface.

 

[Phillbo]

I know for a fact that the leak is not above the pedestal that the tank sits on so I assume I'll have to strip it down to see if it's a crack in the backwash line or a problem at the connection.

I noticed bubbles coming out the return line this morning. I assume the leak is causing them.

I plan to tear it down this weekend and see if I can locate the problem, I'd like to have parts ready so any advice on what to buy before tearing into it would be helpful. Do pool stores sell a pack of the washers or o rings that may be in the connection?

 

[Phillbo]

I was unable to find anyone that had a tool to remove the big nut at the bottom of the tank holding the manifold / o-ring assembly I needed to remove, a couple different shops told me it would leak again so due to the age of the unit, I opted to go for a new unit.

Installed the new Pentair FNS Plus 48 DE Filter last night.