How to LOWER PH?

[bheron]

I've had a high PH problem - its been around 8.6ish or more. I realized it was probably my tap water so I went out an bought 20 gallons of RO water from Walmart. When I tested that water the PH was still around 8.5? I did a 20% water change and my PH is still 8.6.
What can I do to get the PH down? Its the only measurement thats keeping me from having a safe tank.

 

[brooklyn johnny]

What is your alkalinity level? How are you dosing your calcium... with kalkwasser, 2-part supplement? What buffers are you adding? What pH is your freshly mixed saltware coming up with? Have you tested the water reight before your lights come on, and right before they go off at night? My pH fluctuates betweeen 8.0 and 8.3 according to the time of day.
My first course of action here would be to test out the test kit. Either buy another test kit or use a buddies before you do anything drastic. Do you have a pH monitor? They cost about $90 but are a great investment, especially if dosing kalkwasser, and they avoid the old, "Is that 7.8 or 8.0... or maybe 8.2?" You avoid the old color differentiation mess. Answer the questions above. Also how long has your tank been up? Let us know what you are putting in in the way of additives...

 

[shnookums]

i would definitely test the test kit, test the source water before making saltwater, then test the saltwater, process of elimination. we used to use the tablet form of ph test kit, it always tested 8.6, went to the same brand test kit to liquid form and that tests at 8.3. go figure. good luck, keep us posted