Ok, heres the results i got from the tests --
pH: between 7.0-7.2
(did the high range pH to confirm, and it was at the lowest result of that one)
Ammonia: 0-0.25ppm
Nitrite: 0ppm
Nitrate: 10ppm
GH: about 18° (rated on the
Temperature: 81°
The tank has been established for quite a while now, and has 3 broadleaved plants in it (i can't remember which ones, but the fish ate the other ones that were there before, so i've been giving them spinach leaves and some zucchini to try to keep them off the plants)
I just didn't know if this was a common plecko behaviour -- hes swimming quickly to the top, making a splash, then swimming back to the bottom. On average, maybe hes done it 5 times since noon? Otherwise hes just been lurking and letting himself get cleaned by the loaches, and positioning himself at different angles to blink at me.
... and without trying to anthropomorphise the guy, maybe he just saw that i was home and was messing with me