ORP and pH daily dips

[Reeferdood]

At precisely 2:45 every afternoon I get a sharp dip in ORP & pH as seen on the Apex. I use 2 Dos pumps that dose Calcium and Alkalinity and the other does transition elements and Acro power. None of the pumps are dosing at that time in the day as checked in the apex log. Does anyone have any idea as to what could possibly be the culprit? The dips are sharp and short but it is puzzling me as to what might be causing it...
Any Ideas????

 

[TheEngineer]

Nothing is turning on or off at that time?

 

[rkpetersen]

I'm having a hard time coming up with something that would affect both pH and ORP probes, at exactly the same time daily. Can you post an Apex Input Log screenshot of the pattern? First thing I thought of was electrical interference between some device's power cord and the two sensor cords; does anything at all turn on or off at that time of day? Second thing I thought of was whether it was possible that the water level is transiently falling where the probes are, briefly exposing them to air, which could change their readings until resubmerged.

 

[Reeferdood]

Nothing is turning on or off at that time?

Nothing that is being logged, I thought the same thing....

 

[Reeferdood]

I'm having a hard time coming up with something that would affect both pH and ORP probes, at exactly the same time daily. Can you post an Apex Input Log screenshot of the pattern? First thing I thought of was electrical interference between some device's power cord and the two sensor cords; does anything at all turn on or off at that time of day? Second thing I thought of was whether it was possible that the water level is transiently falling where the probes are, briefly exposing them to air, which could change their readings until resubmerged.

The probes are in an area of the sump that has a fixed waterline... I'll take some screenshots and post in a few...

 

[Reeferdood]

 

[rkpetersen]

That is really bizarre. And it doesn't look at all like what you'd expect if something was being turned on/off and then back; the fall is instantaneous while the recovery takes time.

I'm stumped at the moment. I would probably update my firmware, reboot the Apex, and hope it resolves.

(Was also going to suggest that you post to the Neptune forum, but I see that you've done that.)

 

[rkpetersen]

What does your Energy Bar voltage Output Log look like? Particularly at this time of year, many people see a significant drop in wall voltage in the afternoon. Also, do you have your system on a UPS?

 

[Reeferdood]

What does your Energy Bar voltage Output Log look like? Particularly at this time of year, many people see a significant drop in wall voltage in the afternoon. Also, do you have your system on a UPS?

No UPS, I rarely loose power here. I think I am on the same grid as the Space Center....
No spikes at 2:45, I am stumped...

 

[Reeferdood]

After further review and lots of notes I think I have found the culprit!
I am dosing ESV's Transition Elements plus just slightly before the dips. So, it takes this long for it to make it's way through my system and sump before the probes pick it up. The dips started precisely the first day I started manual dosing and got larger when I increased the dosage amount.
I will adjust the dosage amount over a two hour span vs a one time dose of 10 ml. It is hard to believe that just 10 ml of this would have such a dramatic impact on those measurements.... I'll monitor and post results this evening after the new dosing scheme to see if my guess is correct.

 

[rkpetersen]

After further review and lots of notes I think I have found the culprit!
I am dosing ESV's Transition Elements plus just slightly before the dips. So, it takes this long for it to make it's way through my system and sump before the probes pick it up. The dips started precisely the first day I started manual dosing and got larger when I increased the dosage amount.
I will adjust the dosage amount over a two hour span vs a one time dose of 10 ml. It is hard to believe that just 10 ml of this would have such a dramatic impact on those measurements.... I'll monitor and post results this evening after the new dosing scheme to see if my guess is correct.

That makes sense. Look what's in this stuff:

CONCENTRATION: 1ml/20 gals of aquarium water adds a total of 19.4ppb Transition Elements (iron, manganese, zinc) plus 670ppb organic carbon (from citric acid, ascorbic acid, sodium citrate)

IONIC CONTENTS: Citric acid, chloride*, sodium*, ascorbic acid, citrate, sulfate*, iron, potassium*, manganese, sorbate**, zinc
*In natural seawater ratios
**less than 0.05%

Lots of iron to drop the ORP, lots of organic acid to drop the pH.

 

[Reeferdood]

That makes sense. Look what's in this stuff:

CONCENTRATION: 1ml/20 gals of aquarium water adds a total of 19.4ppb Transition Elements (iron, manganese, zinc) plus 670ppb organic carbon (from citric acid, ascorbic acid, sodium citrate)

IONIC CONTENTS: Citric acid, chloride*, sodium*, ascorbic acid, citrate, sulfate*, iron, potassium*, manganese, sorbate**, zinc
*In natural seawater ratios
**less than 0.05%

Lots of iron to drop the ORP, lots of organic acid to drop the pH.

Really amazing that 10ml in a 200 gallon system would do that... It still dips but nice and subtle, no radical dip like before.

 

[Ferrell]

Good info
It’s summertime and summertime means canning fruits and veggies. I notice a big daytime dip in ph when my wife is canning during the day and has the stove on for extended periods. But orp usually goes up when ph goes down

 

[TheEngineer]

Really amazing that 10ml in a 200 gallon system would do that... It still dips but nice and subtle, no radical dip like before.

Does the doser drip close to where your probes are?

 

[Reeferdood]

No, the probes are on the upside of the baffles in the sump. The TE+ goes through the entire system before being picked up by the apex. I backed off the DOS to 5ml and going to watch it some more.. I need to raise my nitrates anyways, this stuff is really keeping my nitrates and phosphates low.
Gotta love ESV, I do..

 

[rkpetersen]

Good info
It’s summertime and summertime means canning fruits and veggies. I notice a big daytime dip in ph when my wife is canning during the day and has the stove on for extended periods. But orp usually goes up when ph goes down

Do you have a gas range or stove? If so, the CO2 concentration in your room air is likely skyrocketing while the stove is on, which will drive down your tank pH.

In our household, it's most often when we're making a pasta dish. I've got a CO2 monitor near one tank, in the family room next to the kitchen, and it always starts beeping at me when I'm cooking sauce and boiling water. I've seen measurements over 900 ppm, yours might go even higher.

A CO2 scrubber attached to your skimmer air inlet would fix this. (Or a just running a hose to the outside.) I use CO2 scrubbers on my tanks, just to keep the pH up a bit, particularly at night when it tends to drop.

 

[TheEngineer]

Do you have a gas range or stove? If so, the CO2 concentration in your room air is likely skyrocketing while the stove is on, which will drive down your tank pH.

In our household, it's most often when I'm making a pasta dish. I've got a CO2 monitor near one tank, in the family room next to the kitchen, and it always starts beeping at me when I'm cooking sauce and boiling water. I've seen measurements over 900 ppm, yours might go even higher.

A CO2 scrubber attached to your skimmer air inlet would fix this. (Or a just running a hose to the outside.) I use CO2 scrubbers on my tanks, just to keep the pH up a bit, particularly at night when it tends to drop.

What monitor do you use? You can always tell when we have people over, the pH in my tank takes a nose dive

 

[rkpetersen]

What monitor do you use? You can always tell when we have people over, the pH in my tank takes a nose dive

I bought this one. It seemed like a decent balance of function, price, and something I could leave on an end table without my wife objecting. Seems accurate enough; responds quickly to obvious sources of CO2, at any rate. I occasionally take it outside to recalibrate, which isn't hard to do. Configurable two-stage alarm level. My baseline level in the house is around 500-550, which seems about right given that we typically keep the ground floor doors and windows closed most of the time. I've also noticed that the displayed CO2 level rises when company comes by! The level last week, when my wife's daughter and her family were here, hovered around 600. Another funny thing - There are a lot of other electronic devices on the same table as the monitor - printer, battery charger, webcam, echo, ipad, etc. If you're having a problem with something and start huffing and puffing in that area while trying to fix it, it can actually set off the CO2 monitor alarm. You're breathing too hard!