Raising KH and other tap water issues.

[jimangie1973]

I have tap water with extremely low carbonate hardness, currently KH < 1 deg. It has a GH of 6 deg. Initially out of the tap it has a fairly high pH, around 7.8. Then as it sits, the pH settles to about 6.5. To add to the problems, the water contains chloramines. After using a general dechlorinator, there's about 1ppm ammonia.

Questions:
1. What is chemically happening to cause the pH to drop from 7.8 to 6.5?
2. Any recommendations on a buffering product to get the KH up without raising the pH through the roof?
3. Is using Amquel/Amquel+ dangerous with such a low KH?

I've started adding very small amounts of baking soda to raise the KH but I'm not sure this is the best solution. I'm now worried about doing water changes larger than about 20%.

Thanks for any help,
Jim

 

[OrionGirl]

1. Normally, the problem is that dissolved CO2 is in the water from the tap and gives a low reading, and then it gases off, resulting in a higher pH. Not sure what would lower it.

2. Baking soda will buffer, or adding sea shells/crushed coral to the setup (could be a baggie in the filter).

3. I'd use Prime, as it will detoxify the ammonia to ammonium--don't know how stable it will be at that low pH, but once you buffer it, should be fine.

 

[RTR]

In many soft water areas, the utilities tend use short-acting buffers to protect the piping networks and home pipies as well. These are largely phosphate-based and very short-lived buffers, just as they are when folks try to use them in fish tanks. Your description of your water matches that profile exactly.

Agree with OG's other points, but if you do use baking soda, add to the tank in small quanties at a time. Large sudden changes can osmotically shock the fish.

 

[jimangie1973]

Thanks for the help. I will stick with baking soda until I can get the KH to at least 2 deg. Hopefully, the pH will not rise too much.

I guess I'll stick with the Amquel as well and keep a close eye on the KH immediately after partial water changes.

 

[hike13]

I'm in the same situation as far as my KH goes. I just got my kh test kit and found that the water out of the tap is about 1 dKH. After reading a few threads here on AC I was considering getting some crushed coral to add to my filter. How much should I start with?? 1 Tbsp maybe and see how that affects everything?? My ph after the tap water sits out is between 6.6 and 6.8 so what level of KH am I looking for in order to maitain that? 3-4 dKH maybe?

 

[Pretender]

jimangie1973,

At first I didn't believe anyone in Florida had such low KH, but I took some water when I stopped at my gym in Melbourne on Friday and tested it at 1 dKH and 2 dGH with my Aquarium Pharmaceuticals kit. I get my water from Cocoa, and I don't have the number with me, but they were more like 6 and 10. I suspect the difference is that Melbourne takes a lot of its water out of Lake Washington while Cocoa and Palm Bay get it from the aquifer. I should test the Palm Bay water at work.

I don't know how big your aquarium is or how practical it is, but perhaps you can get some water from a friend on another water system to mix with yours.