pH swings in small, buffered planted bowls

[Wanda]

In another thread, wetmanNY says he (you) keep a paradise fish in a planted salad bowl. The bowl is loaded with plants, and has some crushed coral (which provides some buffering).

Have you noticed any pH swings between morning and late afternoon? Or does your water have pretty high buffering capacity, which combined with the coral carbonates, minimizes pH changes?

I notice measurable pH swings in my 15 gallon tanks that have live plants, even though some of the tanks also have coral (for my livebearers). The pH is lower in the morning when the plants are respiring and higher in the afternoon when the plants are photosynthesizing. My tap water has very low kH, which contributes to these swings, I'm sure. Maybe I should add more coral ....

Also, typically what is a paradise fishes' lifespan? I've tried to find this on the internet, but haven't been all too successful.

 

[wetmanNY]

Well, my NYC water has very low buffering, and my tanks range as low as pH6.2 in the mornings and get up to 6.8 in the evenings. It's always seemed percectly natural to me. It doesn't take much more than a large escargot snailshell eroding away to keep a 10-gallon balanced in the mid 6s, I find. I haven't pH- tested the water in the plant nursery.

I'll do some tomorrow...

I don't think the Anabantoids as a group are very pH-sensitive. Isn't a lot of "pH stress," actually the conversion of NH4 to NH3 as pH is made to rise? Just a hunch.

I read a report somewhere (Wetzel's Limnology?) of pH testing in a large calm lake, where pH was notably higher near densely weedy areas in late afternoon. Fish were perfectly free to swim from water of one pH to water of another...

Does anyone know the age expectations of anabantoids? Bettas have never lived more than four years with me, if that.

 

[Wanda]

I've only kept very hardy types of fish; none have ever appeared to be pH sensitive. When I started keeping fish though, I was really worried about these pH swings, because just about everything one reads advises keeping pH very stable (which I found near about impossible to do, especially with the water I have). I can imagine, however, that large fluctuations in pH could be a problem for more sensitive types of fish (?), and definitely for saltwater fish.

It makes me feel better to hear that such an experienced and wise fishkeeper experiences pH swings and isn't concerned.

My bettas are definitely short-lived (usually about 3 years). I could be very wrong, but I partially attribute their short lifespan to inbreeding.

I guess I was thinking that paradise fish live longer than some other anabantoids because they haven't been inbred as much (right??) The reason I ask is that my paradise fish, which I've had for almost exactly 3 years, seems to be slowing down a lot lately. I'm trying to figure out if he's sick or old.

Thanks, and am glad to hear the holidays put you in more of a jovial mood (less skeptical, at least!) If you do measure your water params tomorrow, I'll be interested in hearing what they are.

Happy New Year!