Tracking PH thru the day

[whatevva]

I'm trying to determine if the daily PH swing is proper, or if it's just following temperature. I don't know what the normal swing should be. The software has temperature compensation for the probes, but it said to turn it off. The reason for 2 probes is because 1 will eventually end up in the calcium reactor as soon as Precision Marine sends me a custom cover that will allow the probe to be inserted directly in to the chamber.

[ChrisPrusha]

Very cool, Butch!! Do you have a link for the software/probes?

[whatevva]

Very cool, Butch!! Do you have a link for the software/probes?

This is all part of the Neptune AquaController 3 (forget the AquaController 3 Pro, It won't do 2 PH probes and it's $400 more!) The software is called AquaNotes and once you connect via Ethernet to a PC, it logs any chosen parms forever. It all came from Marine Depot.

How about the swing? does it look right? Or does it appear to be tracking temp?

[ChrisPrusha]

Although I am no expert, Butch, I would say your pH readings are reasonable.

Thanks for the info!

[whatevva]

Here's a weekly if it helps. I think it's more confusing. Notice on Wed. that I calibrated the temp on the chiller and the unit ran 1 deg higher. Just a bit of money to be saved on electrical PH probes were calibrated on Sat the 4th

[tdwyatt]

Coincidental that the temp and pH seem to follow each other. The temp is actually following the photoperiod, which IS directly responsible to the pH in the tank. As the photoperiod starts, all the photoautotrophs utilizing chlorophylls start removing the CO2 from the tank water, which drives pH up as the effect continues while photosynthesis turns CO2 into carbohydrates. This will usually end up with a pH value somewhere near 8.4 or so at the end of the photoperiod. After the lights go off, the photosynthetic organisms usually become net CO2 producers during the night as the organisms start to break down stored carbon products for respirations. This drives the pH down during the dark to a nadir of around 8.0 just prior to the start of the photoperiod. Once the lights or sunlight starts the photoperiod again, the cycle repeats itself. Many other factors affect the actual nadir and peak values, but most of them revolve around the concentration of CO2 in the water and how it is affected by processes during the 24 hour day. Assuming that alkalinity, calcium, Mg, and salinity are correct for the tank and there is adequate gas exchange with the atmosphere (and that the atmosphere above the tank is not loaded with artificially high CO2 levels), the swings shoud be within the ranges you're seeing.



HTH

[whatevva]

Thank You Tom, That's what I was looking for.

[VWD]

Pretty cool Butch.

[whatevva]

Pretty cool Butch.

Thanx Vince! I really like this controller. I think the software is still going through some growing pains.

[Loverotties]

Thats neat!