Distilled water and pH

[waynesai]

Hi guys

I have a nano tank and have been using tapwater + seachem prime for topoffs and water changes for about 1 year. Recently, I decided to use distilled water for better water quality. First water change using distilled water so far.

(not intending to invest in a RODI yet)

What I found from google is that distilled water generally has a pH of 6.9-7 while the optimal pH level for aquarium is 7.6-8.4.

Also, while I have test kits for most of the essential water elements, I have not bought the ones for pH.

So my question is, will routinal water change using distilled water eventually bring my water pH to 7? Is there any cause for concern?

 

[waynesai]

Here are my parameters taken today
salinity: 1.025
dkh: 10.7
magnesium: 1400
calcium: >500
phosphate: <0.01

 

[Scrubber_steve]

Hi guys

So my question is, will routinal water change using distilled water eventually bring my water pH to 7? Is there any cause for concern?

No, your salt mix will raise the pH

 

[Ron Reefman]

I used distilled water for a year when I started and I had no issues.

I think if you have good water movement in your tank, specifically water movement that makes the water surface move (like a wavemaker), you will facilitate the gas exchange between the water and the air. The CO2 in your water will lower your pH. The gas exchange will allow CO2 to escape into the air and the oxygen in the air to mix into your water and raise your pH. Water surface movement does this even better than a good skimmer with all it's bubbles.

 

[Randy Holmes-Farley Verified Community Expert]

Actually, adding totally pure fresh water at pH 7.0000 to a reef aquarium at pH 8.2 will actually raise the pH in the aquarium very slightly for well understood reasons (which if you already knew it, makes you a master reef chemist :

Master Reef Chemist Certification Question!!! (yes, you want this title)
https://www.reef2reef.com/forums/reef-chemistry-by-randy-holmes-farley.295/