We already addressed this little tidbit maybe I didn't spell it out but I breed live bearers and tetras. the live bearers that I have love my alkali water and make lots and lots of babies. My tetras however need peat for their tank and get distilled water and peat in their breeding tank. I am testing the stability we are on day 2 going on to three and it'll probably be about five to six days before I really know if this is worth even fallowing through with. Besides a container of vitamin c crystals is about $15 and a little bit goes a long long way while pH down products can be very pricey and in most cases need to be added very often and in larger quantities.
Yes, livebearers do indeed love base or alkaline water. Do you notice a pH bounce when using distilled water for the tetras (are you breeding New World or African tetras?).
My main point was that there are tricks to this that don't require crazy or expensive treatments (such as pH Down, which I HATE, because it allows that bounce and people don't understand how quickly that'll kill their fish). Also, if you're relying on reading that test you took days ago to give you an accurate reading, it's not going to just change on its own. You need to retest.
I worked the aquatic import/export trade after I got started on the miniature reef habit (had to pay for coral
somehow, right?) for quite a few years, so I'm a bit of a fish geek.
I think your best bet is to push the water through some peat. Use an old canister filter, Fluval or similar (Eheims are spendy). That should bring the pH down safely and without the bounce back up.
IF you can find the formulation for it, then I suggest trying a place like
The Chemistry Store.com - Serving The Hobbyist, Student, School and Industry and picking up some acid compounds and mix your own pH down. Just like sodium thiosulfate (dechlorinates your water), the cost is REALLY jacked up for a very dilute solution. For instance, that sodium thiosulfate that's already mixed into a solution and sometimes has other stuff (like StressCoat) mixed in is going to cost you several dollars for a little bitty bottle of the stuff, whereas you could also buy a 2lb. jar of
Na2O3S2 crystals for FIVE BUCKS. That's a HELL of a savings there, and you're working with concentrate, a little dab'll do ya.
Oh yeah, if you DO decide to try it, PLEASE PLEASE PLEASE read the MSDS (Material Safety Data Sheet)!
Found H3PO4 here:
DGR Industrial Products, Inc. :: Generic Chemicals :: Phosphoric Acid, 85%, 500ml