Hey there-

I'm just getting started and I've been using five-in-one test strips from Mardel to test my tank water. The test strips consistently give me an alkalinity of 80ppm, and suggest adding Buffer-up. However, they use a generic "community tank" range, and don't mention goldfish specifically in the literature.

What's a good range for alkalinity for Goldfish? Also the test strips indicate a pH of 6.4, but note that low alkalinity can affect the reading. Using an aquarium pharm. pH kit, I have been getting around a 7.0-7.2

Goldfish can tolerate low and high alkalinity, as long as it doesn't fluctuate

Alkalinity (sometimes named KH or buffering capacity) is the measure of carbonate ion in your water. Carbonate ion is the main buffer in your aquarium to prevent swings in pH. Adequate buffering occurs at levels above 4dKH or 71ppm. So your measurement of 80ppm is good.

If your still interested in raising the alkalinity don't waste your money on "buffer-up". Instead head to your local grocery store and pick up a small box of baking soda. Dip some water out of your tank in a plastic cup, add a teaspoon of baking soda to the plastic cup, stir it until it dissolves, add the water back to the tank. You have just raised your alkalinity! Repeat this whenever you see the alkalinity approaching whatever concentration you decide you do not want to go lower than and you will always be adequately buffered.

KH fluctuation is not that big of a deal in reality. However, if it goes too low (below 4dKH or 71ppm) the potential pH drop could be catastrophic to your tank! So, keeping it steady is wise advice!