View Full Version : Hyposalinity and pH

11/17/2009, 11:52 PM
My sg is at 1.008 hyposalinity. I prepared some "cooked" baking soda and a lil tank water mixture to bring pH to 8.2 range. Everytime I check my pH its really low at 7.8 at one point it was down to 7.4 :(. How do I keep it at a constant level all the time. I'm not home during the working hours to monitor pH. I basically check it before work, when I get home and before bedtime.

11/19/2009, 11:32 AM
I know I am not the only person who has done hyposalinity and have had pH issues. I need to stabilize the pH. My fish are going through stress due to the high pH swings. I don't want them to die. :(

11/19/2009, 11:46 AM
I did a quick google search using your topic and came up with this:


pH Control
pH is hard to control in a hyposaline solution because at this dilution, the buffer ability of the diluted saltwater is not good. Be prepared for this.

Make pH adjustments with pure baking soda (e.g., Arm & Hammer) you find in the grocery store, or better yet is sodium carbonate. Sodium carbonate can be made in the home oven. Take a pound of pure baking soda and spread it out evenly on a large cookie sheet. Put into a preheated oven to 350F. Bake it for 30 minutes. Take the sheet out of the oven, let cool to warm and put into an air-tight, clean container for use. Now the baking soda has been turned into sodium carbonate, a more potent pH + additive.

DO NOT try to control the pH with pH buffer or other off the shelf additives. Use only the two mentioned above or a specific strong pH+ control.

Do not add the baking soda or sodium carbonate directly to the hospital/quarantine tank. Always thoroughly dissolve some powder in RO/DI or distilled water then drip/add that in slowly to move the pH up.

If you mess up and the pH has lowered considerably (more than 0.2 pH units) then raise the pH VERY SLOWLY -- no more than 0.10 pH units per day. A large pH change can seriously harm a fish, especially a sick one.

11/19/2009, 12:52 PM
Thanks, I've read that already. Any solutions to slowly drip so it stays constant without constant monitoring?

11/19/2009, 03:10 PM
Go look at the tubing and RODI parts at your local big box store ;) They have mini shutoff valves for RO lines and the tubing. Or airline tubing with a knot or air valve you have sitting around.

11/19/2009, 03:18 PM
Fish do not need very high Ph, except when you reintroduce it to water of high pH.

7.8, at least, is good for fish.

11/19/2009, 03:27 PM
I've used hypo before but I did not have much of a problem keeping the pH in check. I did read somewhere people used some tubing to set-up a slow drip from a container filled with a baking soda mixture. I think Hellaenergy's idea is about your best choice. You'll just have to figure up a mixture ratio for baking soda/water that you drip into the tank.

If possible you can also try to get some more surface agitation going, maybe that would also help with pH levels.

and +1 to what wooden_reefer said. if you can keep it constant at 7.8 or so the fish will do fine.

11/19/2009, 04:33 PM
I think what I am going to do is fill a 2 liter bottle with baking soda mixture and poking a hole in it and slow drip it with the air line I use for acclimating. I think that might be the cheapest easiest solution for now. I may look into a cheap dosing pump in the future.