Help! Frustrated with ph again - should I be doing this?

jsweir · Jul 15, 2020

Been out for 15 years, remember always struggling with keeping ph up. Fast forward to now I have 3 40 breeders set up for QTs, fully cycled. 240 main display is still going together. Using RO/DI with fritz salt (blue box). PH is 7.5, tried putting it outside with a power head in it for 3 hours - only goes to 7.7. dKH is 8.7. QTs are simple aquarium only with hang on back and two have airstone/sponges. I have no way to get outside air efficiently into them and seriously doubt it will help much anyway. I can't run a scrubber except on the main and I really don't want to burn through media every week. Can't really dose kalkwasser yet because there is nothing in them to uptake and won't be able to run a fuge on the main until the tank has been running for a while and can support it. BTW - ph on my freshwater tanks sticks around 8.2.

Sadly at this point I wonder if I'm just trying to push something that can't happen. Huge investment, but I don't want to be irresponsible and kill a bunch of fish and coral.

Any suggestions would be appreciated - Scott

andrewey · Jul 15, 2020

Hey Scott,

What are you using to measure your pH? If it's a probe, when was the last time it was calibrated?

jsweir · Jul 15, 2020

Using a seneye monitor - I've somewhat verified with a test strip that supposedly does marine as well as fresh, but I guess I should pick up a decent kit today. seneye doesn't have a calibration - I'll pick up a salifert today and report back.

Mattman1977 · Jul 15, 2020

Easy why to test your seneye is ph calibration like for a apex unit or Hanna checker. Both pretty cheap.

andrewey · Jul 15, 2020

jsweir said:
Using a seneye monitor - I've somewhat verified with a test strip that supposedly does marine as well as fresh, but I guess I should pick up a decent kit today. seneye doesn't have a calibration - I'll pick up a salifert today and report back.

I think that's a reasonable approach. Unfortunately, there are a range of activities and variables that can influence the seneye slide readings. It may be accurate or it may not be, but unfortunately without a way to calibrate or verify against a standard, both possibilities are on the table.

These are a couple of "low hanging fruit" items from seneye, but they are not exhaustive for when the seneye may read differently than a standard/calibrated pH probe:

Strange pH/NH3 readings - Seneye

>>>Why is my PH reading strangely on my seneye device<<<

answers.seneye.com

jsweir · Jul 15, 2020

Well, I may have learned a valuable lesson here - I think the seneye is way off in it's reading. Looks to me like the Salifert test shows somewhere in the 8's. That is a huge relief. Going to run the same test on the other 2 QTs and on some outside aerated water.

jsweir · Jul 15, 2020

Pulled out my API freshwater high ph test kit as well (supposedly does fresh or salt) and looks like 8.2 to me

andrewey · Jul 15, 2020

Glad you were able to figure it out! In general, I wouldn't put much weight in any device/test kit if you aren't able to compare the results to a known standard or calibrate the test. So long as the seneye is in line with a validated method, it's a good tool to use, but as you saw here, given the room for error, I wouldn't use it as your "gold standard".

I'd be interested to know what reading you get if you were to change out the slide.

jsweir · Jul 15, 2020

I do have slides on the way so I will be able to tell you by this weekend

jsweir · Jul 15, 2020

Couple more tests - run on water aerated outside for 2 hours. Looks like the salifert is close to blue which would be >8.3 and the api high range looks like it's getting close to 8.4. Seneye reads 7.73 and is slowly going up a bit. You can offset the ph so I'll do that when I get the new slides.