Ph 8

[mattlee]

i set up a tank for my corys a couple of days ago with sand substrate, a piece of mopani, and a piece of bogwood and a coconut cave. i tested the pH before adding the fish and got 7.4 same as my main tank. after adding the fish a donated filter sponge and a sponge filter that has been cycling in 1 of my tanks for a month and leaving for 24hrs the pH now reads 8.....!
my question is why has it risen since adding the fish , sponge and filter?

 

[Harlequins]

Have you got tannins in the water from the mopani?, might affect the colour of the water on testing ph??

 

[mattlee]

yeah quite a bit, thats the look i was after..... didnt think of that! its not too dark yet as only been set up a 3 days but the tank is darker but when water is taken out into the test tube it looks quite clear.

 

[drobbyb]

What is the pH of your tap water?

 

[mattlee]

about 7.6 but it stabalises at 7.4 in all my other tanks. do you think it could be the tannins? will this effect all my tests?

 

[drobbyb]

Tannins won't make your pH go up. They are acidic in nature. I have a feeling that it's probably an ornament or type of gravel or something that is driving the pH up. Has this tank always been like this?

 

[mattlee]

its a newly set up 2nd hand tank (scrubbed and cleaned with water kitchen sponge and a bit of vinegar) with argos play sand (washed), 1 piece of bogwood and 1 piece of mopani wood. thats it! i tested the pH the day before adding the fish and it was 7.4/6 i then added the 2 pieces of wood and the next day added my 11 corys and a hillstream loach. i also added a sponge donated by someone on here (just placed it in the tank) from their filter to help the external to mature faster, there is also a sponge filter thats mature in there.....
so no ornaments or gravel etc!
the thing with the tannins was mentioned saying as the water is darker would the results look darker in the test tube........

 

[mattlee]

can anyone else think of anything? if anything pH should be lower due to the wood.......

 

[OldMan47]

Have you tested your play sand? Just draw some water and split it into two samples. One gets some of the sand added and you test the pH of both samples the next day. Sand is often of unspecified material and it could be limestone if it is a very light color. If it turns out to be limestone, it will drive the pH of the water quite high.

 

[mattlee]

Have you tested your play sand? Just draw some water and split it into two samples. One gets some of the sand added and you test the pH of both samples the next day. Sand is often of unspecified material and it could be limestone if it is a very light color. If it turns out to be limestone, it will drive the pH of the water quite high.

thanks oldman ill give it a go. it is a light colour but i know lots of people add this to their tanks without any probs..... ill try it and report back

 

[OldMan47]

The real trouble with sand is that it is almost always locally sourced and what is available in each location varies quite a bit. If you and I each use exactly the same brand of sand and live more than a hundred miles apart, the bags each of us use probably come from different quarries.

 

[mattlee]

got 2 cups set up 1 with sand and 1 without.... so watch this space!!!

 

[mattlee]

just tested the 2 cups of water and the results for both after 18 hours is pH 8.0...........
my main tank is 7.4 using the same water and when i tested the cory tank before adding the fish it was 7.4 - 7.6........
my tap pH has never read 8.0 before its always been 7.8 ish, is it possible that the tap water has changed?
my main tank has 2 large pieces of bogwood in would they drop it by 0.6?
i did a 50% water change on my main tank and it didnt rise in pH.....!
the cory tank also has a medium sized piece of wood and a piece of mopani in there, would this not reduce the pH?
will my corys be ok at this pH? i have ordered some indian almond leaves to try and keep the stained water after the wood has ran out of tannins will these reduce the pH?

 

[OldMan47]

Tap water does vary some if it comes from a surface source like a lake or even a shallow well. A deep well water source rarely varies much but it is often a source that starts out quite hard with a high pH from being in a rock formation well underground for ages. Around here, people who get their water supply from lakes also get to enjoy a large variation in the nitrate content of their tap water. With spring and summer fertilizing, the nitrates go up and come fall and winter, with no fertilizers being applied to the farms, the nitrates go back down.