Rise in PH

[brittanyb157]

Straight out of my tap the water is 7.6 ph wise, but after a week of not changing the water ( I change weekly ) it is always way up at 8.2. Is this normal over time or does this mean I have something in the tank that is causing it to rise?

I read a previous post from 3 years ago on here that said sometimes straight out of the tap you'll get artificial readings? My serpae tetra tend to get fin troubles and I'm wondering if the high PH is the issue or if they are doing it to one another?

Does it harm my fish then to have a ph of 7.6 entering the tank and then a day later have it as high as 8.2? I realize that as long as the ph is stable then it shouldn't be of high concern, but I can't help but worry.

[RampageRunner]

Brittany,

Such a rise in pH can cause pH shock to your fish. Since acidity is measured on a logarithmic scale, small changes in pH can have drastic effects on your fish; for example, a change from 6-7 means the water is 10x more alkaline than it previously was. A change from 6-8 would be 100x more alkaline and so on, a change in 1 of pH results in a 10 fold increase; this is why pH is so important for biological life.

I'm going to venture and say that something in your tank is the culprit. What is your substrate? Some substrates can contribute to a buffering/alkalizing effect. How big is your tank?

[wondabread]

The same thing happened to me last year. The same suggestions you mention were suggested to me. However, the culprit was a rock (or several) that passed vinegar testing.

I later found out that vinegar sometimes may not be acidic enough cause a rock to bubble.

I took all the rocks out, problem solved.

My pH is 7.8 from the tap and I was climbing into the mid 8s. You say your pH is 8.2 after a week. A swing of .6 pH over a week, in my opinion, is not too bad for everyday normal fish. You did not specifically say you tested your pH after a water change and notice this change.This may not make your fish happy, and may kill some.

Figure out which item in your tank is causing it, substrate, ornaments, rocks, or whatever, and get it out.

[plakat]

Leave some tap water out and see if it changes. Lots of tap comes out lower than what you will measure it the day after. This might be what you are experiencing. There may be something in your tank usually substrate or rockwork that could be dissolving and upping the ph over the week.

Originally Posted by RampageRunner

Such a rise in pH can cause pH shock to your fish. Since acidity is measured on a logarithmic scale, small changes in pH can have drastic effects on your fish; for example, a change from 6-7 means the water is 10x more alkaline than it previously was. A change from 6-8 would be 100x more alkaline and so on, a change in 1 of pH results in a 10 fold increase; this is why pH is so important for biological life.

Ph alone won't actually do much. Yes its logarithmic but fish also evolved having to adapt to changes in ph. Mine fluctuates twice daily usually from 6ish to 5ish and then back up with no problem. You need to find out why the ph is changing. Dissolved solids ie GH are more a problem for fish as they can mess with osmosis and as the ph rises so might the GH.

[Hoppy]

If you have carbonate containing rocks in the tank, the carbonate will slowly dissolve in the water raising the KH, which also raises the pH. High KH can be a problem for some fish, so it is generally a good idea to avoid carbonate containing rocks, or coral, or shells, etc. in the water. The pH itself, as far as I have been able to learn, isn't a problem for the fish. Obviously it is possible to get a really large pH change which could be harmful, but what we normally experience isn't harmful. (A pH below 4.5, for example could be a problem.)

[brittanyb157]

Well, this problem is happening in both of my tanks, a 10g and my 29. I have cheap gravel from walmart in both of them, don't know if that could be the problem? I also have petrified wood in both. Those are the only things that are the same. I have malaysian driftwood in the 29 and manzanita branches in the 10.

When I get home today I will leave out my water and test it the following day and see if it has risen. Now, if it is just the water and not anything in the tank, is this harming my fish? I'll also start testing my water every day and see how much it changes over each day. Hopefully it's slow so it won't be bothering them so much.

[bannh]

If you want to test the tank daily, make sure you do it about the same time every day. Even a non-CO2 tank can have minor pH fluctuations, lower at dawn than after the lights have been on for hours. If you find it's just the pH changing and not the gH/TDS, I wouldn't be too worried about it. I agree with plakat that dissolved solids are more of an issue than just pH. Unless you had a lot of carbonate containing rocks, the rise in pH would be slow, especially since you aren't starting with acidic water. Testing rocks and gravel with vinegar really isn't enough, needs to be something strong like hydrochloric acid (muriatic acid) like for pools to be sure.

[Hilde]

So what was the result? What was the problem?

[tremendotron]

Ping. Any chance the culprit was the petrified wood?

I also have three pieces of petrified wood in my high-light 12 gal, and the pH is an astounding 8.4-ish. I'm going to try taking the rocks out to see if it changes.

[comatoast]

Oh, brother. If petrified wood is a pH booster then I'm royally screwed. I just bought more of it than I can afford as the primary hardscape in a new tank I'm about to set up. Can anyone give a definitive answer on this?

[bradac56]

It depends on what type of wood it is some are better than others.

- Brad

[comatoast]

You mean there's a difference between petrified Oak and petrified Walnut??? And how would you know which is which anyway? Not like you can compare the leaves

[Hoppy]

http://en.wikipedia.org/wiki/Petrified_wood Petrified wood should have very little, if any effect on either KH or GH. Carbonate containing rocks are never, as far as I know, very hard. Even crystal forms of carbonates are pretty soft. Petrified wood is very hard.

[comatoast]

Hoppy, once again you have provided illumination. Thanks.

[Church]

Petrified wood is completely inert. It's nothing more than quartz. I guarantee that is not the culprit here. I'm thinking it's probably the cheap gravel.