Ph question

[Kharrnn]

When I started my tank and was testing the water I was getting a consistent Ph reading of 7.2. Several weeks later though I am somewhere around 8.0. What can cause this, and how can I slowly lower it to approximately 7.0?

About my tank...
10g
Pretty heavily planted with Elodea, Red foxtail, Moss ball, Java moss, 2 kinds of swords, and 2 other plants that I don't know the names of.
Upgraded the lighting to a 72w 4 bulb about a week ago (12 on, 12 off)
Temp steady at 77
3 Otos and ~40-50 red cherry shrimp

From everything I've been reading most plants do best in 6.5-7.2 Ph and the critters I have also prefer lower Ph. I've noticed that the shrimp are not breeding after the first group hatched and I see females with saddles so I know they are ready.

I know I can get peat and it will lower it, I even found this peat ball online that looks awesome, but I don't want to shock my critters so I want to go slowly. Also, I don't want to use chemicals if I can avoid it (and I'm sure it's possible to avoid). I do dose my tank with co2 daily and with ferts, iron and potassium weekly. I tested the tap water and it's also coming up with an 8.0 Ph so I know it's not just my tank.

Any input would be very much appreciated!

 

[Bigge_al]

I added driftwood to my tank to lower the pH but I have not seen any results. My understanding is the tannin drops the pH I may have boil all the tannin out.

 

[BHead707]

what is you substrate? my playsand raised my ph by .6 and co2 should be helping lower it

 

[Kharrnn]

I have eco complete substrate and a piece of driftwood.

 

[BHead707]

also i 'try to lower the ph, if it is consistently staying at the new range it has been at then i wouldn't worry to much, if it starts fluctuating more then you should start to wonder