ph and old peat

Question
Hello Jaymie,

  I have a 10 gal planted freshwater tank that has been running for over 7 years.  Equipment consists of a 104 Fluval canister filter with Fluval carbon, Fluval peat (8 months old), and Fluval ceramic bio cylinders, a 50 watt heater, 2 plant florescent lights (1 3 months old and the other 6 months old), and 2 thermometers (1 stickon and the other in tank mercury).  I also had a Fluval 88g CO2 system running for 2 months as well but removed it in fear that it was contributing to the problem.  Substrate is Eco Complete plant substrate that is about 5 years old.  One large volcanic rock that I had in the tank for most of its life and a medium sized bog log.  I have only 1 sailfin plyco in the tank at this time.  The PH level is on the rise, twice now in the last week i have found it at or above 7.8ph.  I have been using "PH Down" from Aquarium Pharmaceuticals per the directions however by the next morning the PH is on the rise again.  It was 6.8 last night and 7.0 this morning.  My question is will the age of the Peat or the ECO Complete cause the rise in the pH.  Tape water is at 6.8 with low phosphate levels.  Weekly water changes of 25-35%.  Since the addition of the CO2 system there has been a fluctuation in pH from lights on to off, normal for not having the proper controller.  Any Suggestions?

Answer
Deon,
It could be the log and/or the Peat you have in the tank. They have been known to raise the Ph level. It should not be the plants not the CO2. Try removing bot for a day or so and see if the Ph drops back down. Take out some of the water so that both the peat and log are still in water. Let me know how things are going 24 hours after removing them.