API Master says my pH is >9!!! AHH..

[corrado33]

Ok so I'm a bit lax on testing my water, but I wanted to test today. Everything was fine except the pH. Ammonia 0, Nitrite 0, Nitrate @5. The API master said my pH was <9? I tested with a little portable meter I have (pHTestr 2), after I calibrated it with three buffer solutions, and it said my pH was around 8.1, which is fine (although I would expect it to be 7, since I am using RO/DI).

All of the fish are FINE. I don't know WTH is up? I don't know how old my kit is, but I'll check when I get back from the LFS to check my levels. Any ideas what's wrong? What could be raising my pH? I have normal aquarium gravel, driftwood, plants, and one brown porus rock. Admittedly I think it's the rock, as it's the only thing that COULD be raising the pH. (And I haven't tested it)

Any ideas? Uhhh, here's a pic of the rock

My tank when I first started... so clean!


Kinda close up. I wasn't obviously taking a picture of the rock...

 

[Aquarium1]

Well I'm not sure what's causing it but I wouldn't try to change it if I were you. A high stable ph is better than a fluctuating one. Besides guppies like their pH a little on the alkaline side (I'd go with the pH Tester, its most likely more accurate).

 

[mommytron]

that looks like lava rock to me which should be fine. they sell it for aquarium decor at my more local lfs.

 

[jsoong]

8.1 is fine if it is stable.

Check your RO/DI right out of the filter. An old/torn membrane might cause a bypass so it is no longer working properly.

Did you add anything to the RO/DI? <You need a buffer to keep pH stable.> That can up the pH. Also, check the KH, correlate with the pH, that can suggest a reason for the increasing pH.

The next suspect would be the rock. Test it & see if it increases the pH of water in a bucket. <OTOH if the pH is stable, you can also leave things be.>

 

[corrado33]

Thanks guys. The RO/DI unit is brand spankin new so I know the water's fine. I just tested week old water sitting in a closed bucket with a lid and it was around 6.6. (Which makes sense, I'm sure it's absorbed some CO2 from the air) I'm not sure what would be causing the rise in pH in the tank. I want the pH around seven (Lookin for some fishies that like slightly acidic water), although I'm not going to resort to chemicals to change it. It's been 8 for as long as I've had the tank set up. I've always gotten 8 with the API kit though. I'm guessing the kH is the problem, since there is absolutely nothing in DI water.

What can I buffer my DI water with? I obviously have to add something... should I add a bit of tap water? Should I buy SeaChem replenish? Would that work? I was debating getting that anyway. Isn't there stuff called RO-Right?

EDIT: GEEZE WTF!!! I just added pH 6.6 DI water to pH 8.1 tank water and got pH 8.9 water out of the mix??????????? WTH? My poor fishies...

 

[corrado33]

Please see my complete thread over here for a complete description of my tank and it's problems.

 

[krap101]

If your fish look fine, I'm thinking a faulty ph meter?

 

[taylorodw]

I have had some weird pH issues as well with my tank. After getting frustrated, tonight I pulled out every rock and tested them with the nitrate bottle #1 from the API test kit (ChileRelleno suggested it in another thread). To my surprise, a good 2/3 of my rocks were raising my pH!

What really irked me, though, is that I asked the aquarium shop owner if they would change my pH, and he said NO. Either he lied, or didn't know and made it up! Needless to say, the rocks are out of my tank, but it just goes to show you... test your rocks, no matter what your preconceived notions!

 

[krap101]

Well, I think the chemical (compound whatever) that raises pH is calcium carbonate (lime), so just add an acid (vinegar) and if it bubbles, it will raise your pH and hardness.

 

[taylorodw]

I used the nitrate solution #1, which contains a stronger acid. Vinegar isn't acidic enough from what I've heard.

 

[krap101]

Well, it works for identifying aragonite-based sands, which is what I've used it for. Anyways, at least you found your problem

 

[corrado33]

It's not that vinegar isn't strong enough. It just takes longer to react. It's much easier to determine if something has bad stuff in it by using a stronger acid.