I recently found out that many commercial aquarium pH reducing solutions are solutions of phosphoric acid. Adding this products to your aquariums will increase the phosphorus concentration in the water which may cause algae blooms.

I can attest to this, firsthand. Our water's PH runs around 7.8 - 8.0 . We get water from two different wells (municipal supply). Which well we get water supplied from depends on supply/demand in our area as well as maintenance shedules for their treatment plants. Water from one well is at 7.8 and from the other, it is 8.0. Thankfully, about 90% of the time we get our water from the well that is at 7.8. - so there is some general consistency.

At one point we decided to use a PH reducer to "hold" the PH at 7.8. So, whenever we did water changes - we tested the PH at the tap and added reducer to this "new water" in an appropriate amount to achieve 7.8 (before it was added).

At one time I had treated one of my tanks with Dimillin (for anchor worms) - and I was performing daily 10% water changes to eliminate the Dimillin from the tank. At this very moment in time we were switched over to the well that supplied water at a PH of 8.0. By the time I had performed eight or nine 10% water changes, diligently adding the PH reducer, I had a full scale algae bloom.

We have now determined that weekly water changes of 25%-30%, even if the incoming water is at a PH of 8.0 (while the tank stays around 7.8)- is a better solution that tinkering around with the PH.

Actually, unless the pH is below 7 or above 8.5, it's better not to tinker with the pH anyway. GF will happily adjust to a steady pH even if it is outside their preferred range, but they do not do well in a constantly fluctuating pH which is usually what happens if pH adjusters are used.

Didn't know about the phosphate / algae blooms though - interesting!

My pH has been as low as 7.8 and as high as 8.4 as per my tap water and my goldies are fine with it, although I do remember freakingout as a newbie and going to buy some "pH down" as my pH was 8.0..........then I came here, and I never even opened the bottle, its still sitting in my fish box!