Kat, here in sunny, hot and humid central Florida, we frequently have heavy rain. Last summer I noticed my pH would drop like crazy after heavy rain. What I did, and seems to be still working well is to strategically place some highly alkaline limestone rock in and around the edges of the pond. They are above the normal pond level, but during a heavy rain they are submerged for a while.

I don't know about the lava rock, but we get a brownish tint in the pond after the annual leaf fall. Dump a laundry bag of charcoal in your filter for a bit and it will clear up in a few days.

~dianne

Hi
I'm a BIG believer in "Let it be" lol I use a rainwater purge system as my main filtration system. Have also used this on an outdoor aquarium. During one heavy rain I got over 700 gallons of water through the 150 tank in under 1 hour.!! pH dropped from around 8 to 6.8 temp dropped almost 8 degrees. What happened to the fish and plants ??
Nothing , except my tropical fish spawned and had the clearest water I've ever seen !! lol
On the pond I have no way of measuring but obviously depends on the rain and it's 1000 gallons so the percentage of change would be MUCH different.
3 years ago I switched to GF from tropical fish in the pond as I no longer maintain the temps . So far the most notable result is that I have a gazillion new fry and very clear water requiring no help from me !!!
I certainly wouldn't worry about surface rainfall. If you like the look of the water the organics certainly won't
hurt it. I would put the fish in a plastic bag and use a standard float in method. Probably not necessary if the waters from the same source but it only takes a bit of time?? gary

Kashka Kat,

With the source of your water as long as the only rain water that is getting in the pond is what is falling in the PH will not change. If the rain water is flowing into the pond from the surrounding ground that is different.

Anything from the lava rock would settle out of the water.So if the color in the water is not floating particles it is not coming from the lava rock.

Mike

Drat!!! So it�s that blasted pine pollen again � found a layer of it at the bottom of the pond. Just read somewhere that tannin inhibits algae growth. So THAT�S why my pond cleared up - DUH! And here I thought it was because I was such a knowledgeable and talented pond-person - hahaha!.

I thought the tree pollen was done for the year but noooooo. Apparently, it is just being washed into the pond again by the rain �. after 2 months of no rain.

The problem with pollen is there is not only the little tassel things but also a fine dusty reddish brown powder that you can see coming off the tree in clouds when you shake a branch. Anyone out there have experience with pine trees - Am planning to get a skimmer, but is a skimmer is going to catch that powdery stuff? It may be too fine to be caught by any filter medium?

Light amber tea color is nice, dark roast espresso is NOT� I am not convinced that too much tannin is not bad for fish. And, of course, it gets harder to see them!

I have fir trees and pine trees near my pond. My water is always stained with tannin. I have clear water otherwise and my fish are fine. This pond is more than a decade old....