Reverse Osmosis PH drop

**StringCheesehead** · 02-21-2010, 01:18 PM

hi guys. i just got my RO up and running.

once i filter my tap, the ph drops like crazy.

i was doing some reading, and this happens because the filter filters out everything but the CO2, i guess it lets the gas through.. and the ph comes out real low.

i am pumping air with a diffuser into the water, hoping this airation will balance out the PH, i didn't just wanna dump ph up in it

i'm hoping this will work.

if anyone has any helpful info on this matter please share it!

thanks so much in advance3! peace love respect

-cheese

**StringCheesehead** · 02-22-2010, 06:18 PM

ph dropped from 8.7 tap to 5.4

aeration stone for 1 day brought it back up to 6.5

just for anyone that cared to know

peace love respect

**SHARKBAIT** · 05-16-2012, 11:46 PM

I appreciate the info big time CHEESE!! Helps me plan for the future

Plan before you plant!

**Trich Fiend** · 05-17-2012, 02:13 AM

pretty cool info. what r/o system you got. my tap is like 7.4 and after the filter it's around 5.8. i just adjust it with drops of ph up.

**scroglodyte** · 05-17-2012, 02:17 AM

if yer soil is buffered, 5.8ph water isn't going to hurt a thing. don't spray directly on plants maybe, but fine to water with, imo.

**batf1nk** · 05-17-2012, 03:34 AM

Well done for reporting back your findings matey. +rep

**Illegal Smile** · 05-17-2012, 06:02 AM

RO water should be 7.0. Mine is always 7.0. In fact I use it to calibrate the meter.

**batf1nk** · 05-17-2012, 06:58 AM

Originally Posted by Illegal Smile

RO water should be 7.0. Mine is always 7.0. In fact I use it to calibrate the meter.

pH of RO is not always the same, conditions determine the pH. See below from HERE:

Why is the pH of my RO water so low, I'm worried about my Reef Aquarium?

If you measure the pH of Reverse Osmosis water directly from a RO system you will typically find that the pH reads around 6 to 6-5. This might seem like a problem to be adding something with such a low pH to a reef aquarium, but this is not an issue pH measurements of pure water mean very little, as all it takes is a very small impurity or additive to make a large difference in the value. The most influential thing is carbon dioxide, which adjusts the pH to in the region of 6 if left for long enough and allowed to reach equilibrium the PH will rise. The reason that it only takes a small additive to change the pH is the pure water has an extremely low alkalinity (which is a measure of how well the water will resist a pH change). Therefore, the lower the alkalinity the easier it is to change the pH. As for "is this low pH water is actually a concern when adding it to your reef aquarium" no it is not. It will not adversely effect your tank water since the alkalinity is so low and will not change the pH of the reef aquarium's water.

Its also Worth saying PH pens do no read the PH of Reverse Osmosis water very well and they need some dissolved solids to help with a accurate reading

some info HERE as well.