The Planted Tank Forum - View Single Post - problems with Harlequin Rasboras????
View Single Post
Old 02-13-2003, 12:44 AM   #9
Rex Grigg
Planted Tank Guru
Rex Grigg's Avatar
PTrader: (65/100%)
Join Date: Dec 2002
Location: Portland Orygun
Posts: 9,600
Send a message via ICQ to Rex Grigg Send a message via AIM to Rex Grigg

Most fish can handle a 0.5 pH swing with no problem. It varies more than that during the day night cycle in the places most of our fish come from. A heavy rainstorm can cause a 1 point change in small streams in minutes. I run CO2 on three tanks. One DIY (10 gallon) and two pressurized (29 and 55 gallon) and I leave it on 24 hours a day. I get at most a 0.4 point swing in my pH during a 24 hour cycle. That's much less than you are getting by turning it off. I doubt though that the pH swing is what is killing your fish.
Rex Grigg is offline   Reply With Quote