PH drop can’t figure out why

[Vanquishxxxx]

So my ph which has fluctuated between 8.05 to 8.25 for 8 months tanked to 7.9 Thursday night. One light on my algae scrubber went out I thought that was it. Replaced the light the same day. Now for last few days ph has fluctuated from 7.85-8.0. Can’t figure out why the drop. Recalibrated probe same readings.

Have a large derasa clam(about 18-19 inches) which the same night the light went got pissed and decided to make babies and clouded the water (has happened many times in the past 15 years with him, never have seen a drop in ph), maybe that?


180 gallon tank
1.025
8.5-9
450
1350
77.2-78.2

Orp fluctuated low 300s didn’t see a huge drop or increase.

 

[mellotang]

Maybe more time I’m the house since we on lockdown, maybe more people in the house with windows closed consuming O2 and increasing CO2 levels resulting in depressed ph?

 

[Vanquishxxxx]

No more then usual. Have a co2 scrubber. The drop happened in a 6 hour period in middle of night. Tank is in first floor of 2 story house.

 

[Geraud]

Do you have a Calcium reactor?

 

[Vanquishxxxx]

No, 2 part. Soda ash and calcium carbonate.

 

[Geraud]

Manually or automated? I had had my pH drop because my line inside my KH supplement lost priming :/

 

[Vanquishxxxx]

Auto. Checked that. It’s dosing properly and my ph spikes on my ph probe coincide with the soda ash Being dosed so that’s all working like normal.