I have a small .05 acre pond that I am using to grow out some CNBG. I applied lime about 1 month ago and liquid pond fertilizer a few days ago trying to trigger plankton bloom. The water has been a light brownish color intil the last 2 days. Its now closer to a coffee color. I dipped some water up in my hand and it was crawling with nearly microscopic creatures which I am assuming are daphnia. I know they are a desirable part of the food chain and the fish seem fine. Is it normal to have this happen. Pics give an idea of water color.
Tannins mostly from Oak leaves. Aeration can help some by decaying the leaf detritus faster in the water. On the bright side, the tannin is harmless and the stained water usually creates some incredibly dark and vibrant colors in fish...
Thanks. Its definitely in the shadow of some large hardwoods. It seemed strange to me that the water darkened so rapidly after my fertilizer application, but we had over an inch of rain last weekend. The run off may have been a factor. There is a small seep feeding this pond that is completely clogged with leaves. I imagine the rainwater drainage is acting as a fresh supply of leave brew. I'm still curious about the aquatic life. I'll try to get a picture but they are so tiny. If its daphnia as I suspect then presumably there is enough algae present to feed them eh?
Do I stand any chance of inducing an algae bloom in tannic water? I'll try to get some water chemistry readings this weekend. My main goal is just making sure these CNBG fingerlings have ideal conditions to grow quickly for the next few months.
Thanks for the link. Interesting read and images! Makes me want to go full pond geek and buy a microscope. ;-) I don't believe I've tested the water chemistry since my lime application back on 3/26/18. At the time the PH was around 6.5 and KH looked to be below 10ppm. I applied 160 lbs of dolomitic lime in this .05 acre pond.
Video that shows what I am seeing. This is just a random scoop of water. The entire pond is like this. Close up pic also attached. Pretty sure these are daphnia but can someone confirm?
As a follow up, my water tests from this weekend showed a PH around 7.5 with KH readings somewhere between 20 and 30 ppm. That's definitely an improvement from the pre-lime treatment a little over a month ago. I also did more sampling and the pond is not completely infested with the "water fleas" as I originally feared. There are pockets where they are very dense but it seems to be mostly on the downwind side of the BOW and confined to the top 6" of water.
So despite the brown water color, I think my pond is in a fairly healthy state.