In the window tank again. I am getting frustrated with it. Have the impeller fitted snug again and removed some of that extra media that was probably slowing it down (leaving just fine floss, medium and coarse sponge rubber-banded together on the panel), flow is much better, fishes are breathing normal rate -except for one cory who looked weak and Fabio who was swimming in front of the output again. Film on water surface much diminished. I am suspecting that is from the wood stain fumes off my tank stand still present in the air- it is getting less and less each day but I am still pulling film off the surface with paper towels every morning. Especially since I learned that it blocks oxygen exchange at the surface- and I do notice my cories get frisky after I clean the surface off. Yesterday it even looked like two of them were flirting! Swimming side by side with their pectoral fins quivering.
But I am not satisfied. When I do put the tank on the new stand, that internal filter will be a real eyesore. So I ordered an internal box corner filter. It is cheap because doesn't come with media but I have intention of cutting down the media I already have to fit- already populated with the benficial bacteria. I really like the principles of how the old-style filter functions. It's air-drived like my sponge filter in the betta tank.
I thought perhaps part of the reason the cories still appeared to be breathing hard and darting to the surface frequently was due to the plants not photosynthesizing enough? I removed the background panel and diffused the window light with two more sheets of plastic (one over the window pane, one on back of tank) but noticed it made the tops of the hornwort stems droop. Probably they felt a shortage of some nutrient when faced with the higher drive of light, however slight. This morning I replaced the background, plants perked up again. Guess it's best to keep this tank relatively dim.
Inspected my filter again. Figured out all this time I've had the water level relative to its output wrong. Filter was sitting too low, so the water wasn't going through the media panel properly. I figured this out because lowered the water level last night in attempt to oxygenate more. This morning cleaned up a bit of plant debris when adding more hornwort cuttings from the thirtyeight, and emptied the filter box to siphon out and see how much debris was collecting in there. Water has cleared up- no longer hazy. Rinsed the floss and sponges very gently- and saw that the entire surface of the floss was brown. So now it is filtering properly (before only the edges of the floss panel were turning dark from mulm getting trapped- I should have realized!)- but probably too late for poor Fabio. The weaker cory looks okay now, the one with fungal spot on fin is better too- but Fabio's tail has continued to degrade. He has lost over half his lower caudal fin, the 'sword'. Fungus patches on that have disappeared since I got the water quality improved, but I don't know if he will recover enough to grow it back. I put a baffle on the filter output to gentle the current for him. He moves around easier now but isn't eating, spitting out food...
~ on a more positive note, I've once now had a catfish nibble at my hand when I was working in the tank- that was a little surprise. It always feels like a friendly gesture, although I'm sure the fish was just testing to see if my skin surface had anything edible. I really like my main tank, today. Nitrates higher than I expected- near 40ppm- but everything looks healthy, trimmings were minimal. Black algae spots on the glass diminshed, too. Hornwort still has short, dense foliage. The apono leaves are now long and trailing across the water surface. I kind of like that. It's fun to see shrimps and kuhlis resting or walking across the horizontal leaves up there. It does block light from lower plants- my crypts grow more upright now- which I actually prefer- and maybe it is helping reduce the algae on plants below. So have not yet done a serious trim on the aponogetons.
Had my hand in the tank to trim a leaf and felt a tickle on my arm. Looked down and there was an amano shrimp walking on me. I laughed, until it took an experimental nip with the tiny pincers! That did smart! I shook the shrimp off gently and it scuttled away. Funny.