Pressure gauge and placement - inground system

SpringHillDave

New member
Apr 29, 2019
4
Spring Hill, FL
A quick background of equipment. I have a Harmsco 75 stainless steel cartridge filter system. There is no spot where a pressure gauge can be placed without drilling and tapping the case lid, which I really don't want to do. I do have, on the back side of the cartridge housing, a spigot to drain the pool using the pump, located on the bottom rear of the housing.

My question is this. Can I attached a pressure gauge to the spigot to read an accurate housing pressure when the spigot is open? It seems feasible but I wondered i anyone has done this and the results that they got.
Thanks.
 

SpringHillDave

New member
Apr 29, 2019
4
Spring Hill, FL
I do not see why not. It may not be perfect but it would give you a relative reading, which is all you are looking for.
To confirm - the spigot is on the pump side of the filtering element.

Welcome to the forum!
I suggest you read ABC's of Pool Water Chemistry and consider reviewing the entire Pool School eBook.
The spigot is at the base of the cartridge canister. Last time I used it was to drain the pool for an acid wash.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,784
Laughlin, NV
As long as it is on the pump side of the filter element you are OK.

In the future I suggest using a sump pump to drain the pool.

Take care.
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
22,069
San Dimas, CA (LA County)
Yea, that was a one time thing years ago. The spigot is at the rear of the canister and the pump is to the right of the canister. Does this pose a pressure reading issue?
What matters is whether it's on the clean side or the dirty side of the cartridge. Right or left is meaningless without an exploded view or a photo of the thing taken apart.

If it's on the dirty (pump) side, you're measuring the total pressure in the system, and it will climb as the filter gets dirty. If it's on the clean side, you're just measuring the resistance caused by a heater and any valves and bends and the plumbing itself and any return jets. The fixed cost, as it were, of your system, that's there no matter how clean or dirty the filter is. It's meaningless, and it won't change unless you make physical changes like closing a valve.
 

SpringHillDave

New member
Apr 29, 2019
4
Spring Hill, FL
Thanks, that makes a lot of sense. I'm going to find an exploded view of the canister and follow the pipe to the spigot. Much appreciated.

Update: Checked with the mfg and got under the unit and it is on the feed side so I will need to check pressure to make sure it doesn't get higher than allowed, not using the exit pressure.
 
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