Maybe this subject came up because of something I posted yesterday regarding algae that I thought was possibly due to lawn fertilizer runoff.
With that said, it may not be all bad that you do have runoff into the pond, if it is done in moderation, and if you use something more than a real high nitrogen fertilizer (the first number). High nitrogen is what provides the green, fast growing grass, but it will also cause algae growth in your pond. It is also what runs off the most because it is generally slower to get absorbed.
Your pond will get a good bloom from phosphorus (the middle number in fertilizer). This time of year, a good bloom can be good for the young fish. But, phosphorus also causes filamentous algae.
The third number, potash, is for root growth.
Unfortunately for Bermuda grass, the recommended fertilizers are usually something like 20-0-15. Regular lawn fertilizers are more like 40-5-2.
Do a soil test. See what you might be lacking. Then look for a more balanced fertilizer, without real high nitrogen. Make sure you pond gets some of the phosphous. It will do two things, it will give you the bloom you want, but that will also limit the water clarity. Limiting the clarity will cut down sunlight penetration, which should help keep the potential algae down.
Thing about liquid fertilizer. Liquid fertilizers are more difficult to apply, but they will be at much lower concentrations, and should have a lot less runoff as they soak into the ground. They will also have to be applied more often.
And, as said above -- avoid the weed killers anywhere near the pond.
Hopefully, this didn't confuse too much.
Regards,
Ken
