which water for water changes?

[James_in_MN]

The tap water at my apartment tested at the following:

7.8 pH
8[FONT=Times New Roman, serif]°[/FONT] GH
8[FONT=Times New Roman, serif]°[/FONT] KH

Thinking that would be too high for the fish I was looking to add (black neon tetra, ghost shrimp, otto cats, dwarf gourami, and either glowlight or gold tetra), I started my tank with 60% tap and 40% RO water (with Kent RO Right and pH Stable added to the RO water only before combining).

My aquarium now tests at:

7.6 pH
4[FONT=Times New Roman, serif]°[/FONT] GH
5[FONT=Times New Roman, serif]°[/FONT] KH

I believe that I have three options for water changes in the future. I'd probably change 25% at a time.

1) 100% tap water, which would send the pH back up to 7.8 over time.
2) 100% RO water, which could drop the pH faster than the fish would be able to handle. Am I right?
3) 50% tap and 50% RO water. I'm of the opinion that this would be the safest path if I were looking to slowly lower the pH, if I should even do it at all.

My preference is to not dump a bunch of chemicals into my tank to try to force the pH to be at 7.0. I'm an aquarist, not a chemist.

Thoughts?

 

[maxst2]

Aim for a STABLE pH. NOT a certain number, unless the fish you have really require it. Most don't...Its all about stability.

And I agree with you... no chemicals!

Only thing I use is Prime...which is to dechlor.

I think you should work on raising the pH... so 50/50... then 60/40... till you go right from the tap 100%.

 

[Floyd R Turbo]

Just use the tap water, it's fine. Don't use RO water, it has no buffer and your pH will tank down low. My tap water is 9.8 out of the tap, tank water before a PWC is around 7.4-7.6, 24 hours after a PWC it's about 8.2 then 7.8 after about 3 days.

pH will vary out of the tap as the water is usually low in oxygen. If you want to get a true read, fill a 5g bucket and put a power head in it pointed at the surface for 24 hours then test the pH. It will usually be higher. Why mine is 9.5 I don't know. But it drops out pretty fast.

 

[Tropical boy]

With most fish I would say get ph stable as the recommended ph I what it would be in their wild rivers and lakes, however most fish you buy at the lfs are captive bred and have never been in the ph they should have been.

 

[ejaramillo01]

+1 to stable ph, rather that targeting a specific number, tap should be better than mixing.

 

[James_in_MN]

Thanks for the responses guys. I'll stick with my own tap water.