Pea soup

Quick update post-heatwave. We’ve got a veritable pea soup on our hands.

I tested the water again today, just for fun. I’m getting ready to buy a batch more plants to reduce the algae, I’m thinking several lilies and a few marginal grasses, and perhaps a few more creeping jenny. Cleared a lot of the decaying organic matter out today too, which should take some of the nutrient load out with it.

Results are as follows:

	15 Jul	19 Jul
pH	9	9
Ammonia	2 ppm	0.25 ppm
Nitrite	2 ppm	0 ppm
Phosphate	5 ppm	1 ppm

Genuinely encouraging, despite the green water. Ammonia has dropped from 2 ppm back down to 0.25, and nitrite has gone from 2 ppm to zero. That’s the nitrogen cycle catching up: the bacteria that convert nitrite to nitrate have established, so the spike from the die-off is clearing. Phosphate is the headline though, down from 5 ppm to 1, the lowest it’s been since I started. The clear-out and the plants are pulling it out of the water faster than it’s going in. So the paradox of the day is that the pond looks its worst and reads its best.

The one number that won’t budge is the pH, still stubbornly at 9 after four weeks. That remains the outstanding issue, almost certainly the concrete leaching lime, and the one thing the plants can’t fix on their own.

I did a bit of rearranging, as the lily is spreading out quite a lot now, as are the floating hearts and mare’s tail. The creeping jenny had a lot of algae on the leaves so I raised it out of the water a bit, along with the Veronica beccabunga and the fibre optic.

Good to see the floating hearts (Nymphoides peltata) are actually thriving. Here’s a pic showing their root system sending up new stems.

Finally, I’m still a bit unsure of the progress of the water starwort (Callitriche sp.). Only a few stems seemed to be anchored, so I took the floating clump and placed it on one of the fountain tiers, as apparently it appreciates a flowing-water environment.