outside air to skimmer - sudden drop in ph

[rck329]

Has anyone ever had a sudden ph drop with running outside air to their skimmer?

Last night at 3am, my ph took a detour down sharply. It had been running very steady up to that point with minimal diurnal swings.

Alk is a steady 7.6-7.8

Nothing seems to be malfunctioning - kalk dosing on a pump, no ATO, skimmer running, powerhead running.

Initially I thought the ph probe was malfunctioning, but I checked with another calibrated probe and it's reading the same.

Something in the outside air???

 

[Randy Holmes-Farley Verified Community Expert]

Seems unlikely to be something from outside unless some exhaust pipe is near your inlet. Gas dryer? Car? Furnace?

 

[Randy Holmes-Farley Verified Community Expert]

Might be electrical interference.

 

[rck329]

Seems unlikely to be something from outside unless some exhaust pipe is near your inlet. Gas dryer? Car? Furnace?

hmmm, nothing near the inlet. Can't think of a CO2 source that would be nearby.

The tank is in my basement and my ph was running lower than I wanted so I ran a 2" PVC pipe through the end joist and outside. (it was a 10 ft run and I want to use it for another tank hence the large size - kind of like a plenum) I put a screen over the end to keep critters out. It's about 12" above grade on the outside.

It's almost like my skimmer shut off.

As for EMI, LED's were off so ballast shouldn't have been causing it... I'll have to snoop around a little.

Thanks Randy!

 

[Randy Holmes-Farley Verified Community Expert]

Check to make sure nothing is blocking the air flow in, like a leaf that blew into the opening.

 

[rck329]

Back to normal and no problems. Weird. Maybe something was blocking it temporarily. Or a deer was breathing into it for 4 hours.

 

[Randy Holmes-Farley Verified Community Expert]

Or a deer was breathing into it for 4 hours.

That's probably it.

 

[Insane320]

Question does it matter if we get the air from the outside or can we get from the attic???? @randyholmsfarly

 

[PedroYoung]

Question does it matter if we get the air from the outside or can we get from the attic???? @randyholmsfarly

I use the crawl space under the house and it seems to work. If the attic is vented to outside (which most are) it should be fine. You are trying to avoid the recirculated CO2 from animal respiration in a tightly insulated house.

 

[Insane320]

I use the crawl space under the house and it seems to work. If the attic is vented to outside (which most are) it should be fine. You are trying to avoid the recirculated CO2 from animal respiration in a tightly insulated house.

Thanks, PedroYoung it is a lot easier to pull from the attic, rather than the outside, but I wanted to make sure I get the full benefit.

 

[PedroYoung]

I saw about 0.2 pH shift after running airline into the crawlspace from 7.9/8 range to 8.1/8.2 range.

 

[Randy Holmes-Farley Verified Community Expert]

Question does it matter if we get the air from the outside or can we get from the attic???? @randyholmsfarly

It may depend on where the attic air mostly comes from. If it drifts up to the attic from the home air, it may still have elevated CO2.

If it is flushing with outside air through vents and such, then it is fine.