3.7 ph?

[Wasafooser]

I'm at a friend's house. He has a 70 gallon tank with some neons, white clouds, and other smaller tetras. Did a water change and gravel siphon a month ago. We just checked the ph with a blue lab ph pen. Showed tap water to be 6.5 but tank reads 3.7. I have had fish for over 50 years, ran a pet store for 10 years with over 100 tanks. I'm going all in that there is no way possible these fish could even live below 5.0. Going for a different kit tomorrow. Anyone think this reading is possible?

 

[Seisage]

There's no way... That's basically vinegar! Do you know your typical tap water pH? 6.5 would be low, even for me living in a place with incredibly soft water. Mine tends to sit pretty comfortably at 7.2
Does your tap water or the tank water have any tannins in it, do you know?

Definitely recommend testing again with something different though...

Edit:
p.s. this section of the forums is used for keeping journals of aquarium/fish care and projects. "Tropical discussion" is a good place for general topics and questions, although if you want to make a little journal out of monitoring the pH of your friend's tank, I'd follow it lol

 

[WhistlingBadger]

Welcome! I would definitely get a second opinion. SeriouslyFish says that chocolate gourami and other Malaysian/Indonesian blackwater fish thrive in pH as low as 4, but even that is on the lower end of where they'll live. I'd be interested to see what a different test says.

By the way, Seisage is right. I'll move this thread to Tropical Discussion, where it will get a little more attention.

 

[jaylach]

Did you test the tap water straight out of the tap? If so you can't rely on the test result. When testing tap water you need to put some in a container and let it sit for at least 24 hours and then test. The difference in results can be dramatic.

 

[TwoTankAmin]

I have worked with ALtum angels- both wild ones and also tank bred ones which is what I have now. As for ho low a pH fish can liive in and not die, I suggest you load this paper:
Winemiller, K.O., López‐Fernández, H., Taphorn, D.C., Nico, L.G. and Duque, A.B., 2008. Fish assemblages of the Casiquiare River, a corridor and zoogeographical filter for dispersal between the Orinoco and Amazon basins. Journal of Biogeography, 35(9), pp.1551-1563.
https://www.academia.edu/download/5...the_Casiquiare_River20161111-12340-iedx77.pdf

When you do, head for Table #1 on page 4 where you will see it shows the last 5 river drainages have an average pH between 4.2 and 4.8. Some test sites had a pH as low as 4.0.

 

[Sir Guppy]

If the readings are true, I never knew a p.H could get so low. I thought maybe a perimeter of 4.5 would crazy!
Learn something new every other day in fish keeping I guess.

 

[I Like Rare Fish]

3.7 is basically not possible!

 

[jaylach]

3.7 is basically not possible!

Oh, a PH of 3.7 is quite possible and even a PH of 0.0 is possible. Of course a PH of 0.0 would pretty much equate to car battery acid and probably not good for critters.

Ya, I agree, in household conditions you are not going to see a PH of 3.7, just don't see how it would be possible unless there was something seriously wrong with the water supply.

 

[AJ356]

3.7 is basically not possible!

It's possible

 

[I Like Rare Fish]

Oh, a PH of 3.7 is quite possible and even a PH of 0.0 is possible. Of course a PH of 0.0 would pretty much equate to car battery acid and probably not good for critters.

Ya, I agree, in household conditions you are not going to see a PH of 3.7, just don't see how it would be possible unless there was something seriously wrong with the water supply.

It's possible

Yes, I know what ph is, stands for potential hydrogen, base vs acid, yada yada, and things in everyday life have phs of 1. What I mean is that it is not possible for a household Ph to be 3.7, especially when the tap is not anywhere close to that. Unless he cuts his water w lemon juice, I would retest with a new tester

 

[StevenF]

It is possible I use RO water and have to use a GH booster to increase GH. Early onI used a sulfate GH booster nd found my PH was fine right after a water change but over time it would slowly drop. If It did observe the PH dropping all the way down to 5. I eventually dertimmined it was the GH booster and my plants.

Plants need calcium and magnesium . GH booster does supply these but GH boosters often have a lot of sulfate or chloride in them. Plants need a lot of calcium and magnesium but very little sulfur or chloride. The plants would take in what they needed and then would expel what they don't need. Mainly sulfur and or chloride which would slowly push the PH down. If you don't check the PH periodically you could miss this. i saw no effect on my fish.

I solved the problem in my tank by putting a sea shell in my filter. Sea shells or crushed coral are made of calcium carbonate. The shells only dissolve in acidic water and in doing so they neutralized the acid and the water stays near a PH of 7. That was years ago. Now I make a GH booster made with calcium gluconate and magnesium gluconate. I dump it in the tank dry and dissolves in new minutes. Gluconate is a type of sugar which plants and bacateria will consume (great source of carbon). As the gluconate is destroyed and Calcium and Magneiusm turn into Calcium and magnesium carbonate dissolved in water. Much of the Ca and Mg in rivers and lakes is dissolved carbonates.

 

[StevenF]

Another possibility is that if using an electric PH meter it either needs to be calibrated or the sensor needs to be replaced.

 

[Colin_T]

definitely possible if the tank isn't getting big regular water changes and has a low KH. lots of food going into the tank will help drop it faster if there's low KH.

and a possibility of a faulty pH meter or needs calibrating as mentioned by StevenF