Originally Posted by NFish
So what can I do? She does not want to be using chemicals to raise pH. I read that adding chemicals to raise pH will only temporarily raise the pH and then it will lower and then you add more chemicals and so on. So you end up with constant pH flunctuations.
For basic community fishkeeping, it's best to have the pH of the tank the same as the pH of the tap water. Have her do 20% water changes, no more often than once a day, until the pH of the tank is slowly brought up so it matches closely the pH of the tap water. She'll be getting rid of nitrate, phosphate and other stuff not needed or wanted in an un-planted tank as an added benefit of these water changes.
After that, I'd suggest she do 20% water changes a couple of times a week (at least once a week) to keep her un-planted tank's water free of "pollutants" (planted tank people call them nutrients
) and fish friendly.
Two inexpensive (free actually
) water quality tests:
1) If the water has anything more than a slight and not unpleasant odor, change 20% a day until the odor goes away.
2) Watch the bubbles coming up from an airstone to the surface of the water in her tank (or swirl a net handle in the water to make bubbles). They should pop almost immediately upon reaching the surface. If they don't pop almost immediately, do 20% a day water changes until they do.
I say 20% because changing that amount is virtually always safe... it's not going to change anything in the tank to radically all at once (like pH for example).
Don't calculate 20% based on the tank's rated size. You calculate 20% by measuring the distance from the top of the gravel to the surface of the water (when the tank is what you consider "full"). Then come down 2/10ths of that distance from the water's surface and put a piece of scotch tape somewhere on the side (out of plain sight if you prefer) so the top of the tape is 2/10ths of the way down from the surface of the water. When you siphon out the water, siphon down to the tape mark and quit. Then refill. You've done a 20% (based on actual volume) water change. Actually, it's just a tiny bit under 20% because the gravel doesn't displace 100% of the water at the bottom of the tank -- but better to be a little conservative.
One last item that shouldn't be too much of a concern - but you should be aware of it. Unless she replaces evaporated water with distilled or RO water, the GH and KH of the tank will rise over time above the GH and KH of the tap water. There is no getting around this without distilled or RO water for evaporation refills (or using chemicals - yuk). It's going to happen. However, it will plateau at some point because the tank water will get enough "harder" than the tap water that the water changes take out as much or more minerals as the tap water evaporation refills and water change refills put back. The more often she changes water, the less the difference between her tap GH/KH and the tank GH/KH.