ph dropping on an old tank

[cabana boy]

I have a 6 yr old 20 gallon w/ 1 pleco, 5 harlequins, 2 barbs, flugal 204, 1 mid size driftwood. slowly the ph has been dropping. no new changes to the tank has been made. ph ok for 5 1/2 yr. -no problems. no idea? anyone?

 

[shawmutt]

how often do you do water changes?

 

[cabana boy]

20% once a week like clockwork

 

[shawmutt]

how much has the pH dropped? over how much time?

 

[cabana boy]

steady 7.0 for years now hovering around 6.4-6.5. combating with "seachem ph.7 neutral regulator" . local water is 7.5

 

[cabana boy]

over the past 6 months I have seen the drop.

 

[shawmutt]

did you test your nitrates? From the research I have done, I found this website

http://www.bestfish.com/oldtank.html .

hopefully this will be helpful

 

[cabana boy]

thank you for the responses. nitrates are fine - I will go check out this web site

 

[mendhigirl]

Hey Shawmutt,great site! I hope it helps cabana boy,because I think it's going to help me a great deal! I've had the same trouble with my goldfish tank.Been running for years,all 3 fish seem fine,I change water,clean filter,vac gravel regularly.But past 3 months the pH has gone slowly from 7.5 to 6.6.
I can only assume I need to do bigger water changes.
Old Tank Syndrome is a new one to me!
Thanks again!Kudos 2 you!

 

[littlelouie]

Top link shawmutt, thanks for sharing. I found it very informative and as a warning as I am a newbie still.

Thanks
Louise

 

[cabana boy]

great website good info to keep in mine but my ammonia and nitrates are fine??
going to try reboiling process on drift wood - i noticed that its being to break off pretty easy - maybe after long periods of time they deteriate and begin acidifing water in a greater degree or -----may be the county changed the water quality make up.