DIY pH testing-- Cabbage water

[Cichlidsrule]

This is an easy and fast way to test the pH of your tank without having to go out and buy those expensive kits.
1. Buy some RED cabbage (it won't work with regular), throw about five or six leaves into a pot, and boil it. With water, of course.
2. You should see the water start to change color in about two minutes, but it takes about fifteen to get it a good and dark blue (it should be almost purple).
3. Once the water has turned a dark blue, remove the cabbage leaves from the pot.
4. Measure out about 3 drops of your tank's water into a dish. Add about 3 drops of the cabbage water. If the tank water turns pale pink, your water is too acidic. If the tank water turns pale green, your water is too basic. If the water color stays dark blue, your tank water is neutral.

[Buggy]

Now thats a cool idea, I may just have to try that. Have you checked it against the chemical test kit to see how accurate it is?

[harif87]

That sounds radical. Got to see if that works.

Could the cabbage water be stored?

How big of a pot of water do you boil it in?

[Cichlidsrule]

Yes, cabbage water can be stored-- in a CLOSED container in the refridgerator. It should stay for couple weeks.

I wouldn't boil too much, as you only need a few drops. A small pot should do the trick.

And yes, it works. To see it in action, put it in a few drops of vinegar & watch it turn bright pink!

[harif87]

Originally Posted by Cichlidsrule I wouldn't boil too much, as you only need a few drops. A small pot should do the trick.

I would imagine that the concentration of the "red stuff" would affect how easy it would turn (or resist turning) colors. And if it turns pink,exactly how acidy is it? i.e. what pH is considered color turning?

[wm_crash]

Howdy,

Red cabbage soup as pH meter was one of my high school chemistry experiments. The tough part was to do the calibration. I remember that the color code results varied wildly amongst the groups in the class, but I don't know what the variation was due to.

Also, even with a calibrated solution, you get rather coarse grained pH readings, probably good within 1.0 pH unit.

My take on it is that it's fun, but not good enough if you actually want to know your water pH.

cheers,
wm_crash, the friendly hooligan
AKA #08840, SAA #162, SVAS #120, HOOLIGAN #1
Wilmington, DE

[Cichlidsrule]

Originally Posted by harif87 I would imagine that the concentration of the "red stuff" would affect how easy it would turn (or resist turning) colors. And if it turns pink,exactly how acidy is it? i.e. what pH is considered color turning?

Yes that is a downside....cabbage water doesn't tell you exactly what the pH is. It just tells you if it's too acid or too basic. It would be a lot easier if we had some universal indicator or something....but it's still very useful, as it does enable you to find out exactly why your fish might be acting weird

[mousey]

At the price of red cabbage it would be cheaper to have a test kit on hand. Only useful if you want the cabbage to eat.

[bigdog-ct]

Outstanding Idea

[Ricker]

Will this work for SW to or just FW. Cause if so I am going to tell all my friends. May I ask how did out. Raniny day? lol