Here's the deal

[saberry]

As per some of your advice, I have done a partial water change to lower my pH and water hardness - about 20% replaced with RO water. I am letting the new water cycle for a few hours and then I am going to test the pH and use pH down by Aquarium Pharmaceuticals to lower the pH. As it stands, prior to the water change, I was at an 8.1 and need to get down to between 6.8 - 7.0.

The directions say to add two drops per U.S. gal (55 gal tank), and then to take another pH reading b/4 making the next addition of pH Down. I am not restricted on how long to wait since there are no fish in the tank but, of course, I will let it circulate for an hour or so b/4 each additional dose.

My question is, how much of a drop should I expect with each dose?
It does not say anywhere how much of a drop to expect. I want to make sure I don't overshoot right off the bat. Of course I know the hardness, hopefully lower, will effect the pH outcome as well. I am just hoping someone with some experience with this product might give me a guestimate.

Thanks all

 

[Allivymar]

I'm guessing they don't say how much to expect because it strongly depends on the water's buffering capacity. I don't have a complete handle on this yet (for some reason I can't wrap my brain around it yet LOL), but if your Kh (carbonate hardness) is very high, its tough to change Ph. Generally very hard water (high Gh) has a high carbonate hardness (Kh). What seems to happen is nothing changes for a while, until the Kh is all depleted, the boom. Ph drops drastically and the water becomes unstable. I'm sure someone else will come in and explain this better then me LOL

 

[AtodaJ]

I've used the stuff and Allivymar is right on the money... as usual.

If you test your water and your kh is still high then don't waste your bottle of ph down cuz it won't work... lol. I performed massive water changes with distilled water until I got my kh down to around 5 (20% water change isn't going to do it). Then I used the ph down to get the ph to where I wanted it. It was trial and error for me on how much. As such I'd just follow the directions and keep testing the water. You'll soon figure out how much effect the ph down has for your particular water. Of course, I got lazy and bought a ph regulator not so long ago which sets my ph at 7.0 automatically for me!

If you aren't willing to use natural means to regulate your ph then I'd go for a ph regulator like Bullseye 7.0. Just keep your kh down and include the regulator in your water changes (so it doesn't get diluted) and you'll be fine.