angel questions

My angels are still so shy. I don't know if too many kids rapped on the tank while they were little at the fish store, or is it something I have done. Accidentally squeaked my finger on the glass one time, and they fled from me for days after. Took out all the sticks the other day- reasons below- and now they shy away if I raise my hand to put food in. Half the time they are pale like this-

It makes me sad. And now the larger, handsome fish has a bit of gill curl- you can see the edge slightly lifted, light reflecting off it in this pic.

I tested the water- zero ammonia or nitrites but surprised to find 20ppm nitrates. Is it my fault. This past week I was doing 25% wc instead of 33%- and I was a day late with one of them. I thought that would be fine since I was feeding less- they don't seem as hungry anymore- but maybe not. Went back to doing a 33% wc. Also concerned the outer layer of sticks was breaking down- maybe that was adding too much organics to the water? I lifted them out one by one, rubbed the dark mushy layer off, and returned only half to the tank.

So now they don't have as much cover- but I've seen plenty video of angel pairs in completely bare tanks, who are not shy at all. I thought having mine in a secluded hallway would be best for them, but maybe that means when foot traffic does come through, it startles them? If my youngest comes to talk to me in the downstairs hall and starts gesturing with her arms, the fish panic. I sit in front of the tank as often as I can, having my lunch or doing some small task with my hands, can't tell if it helps. In all that time I spent taking photos for this post, my nicest angel only colored up once:

They aren't as eager to eat, now. I thought because not growing as fast. They don't seem to like the brine or mysis shrimps, but still snap quickly at beef heart and bloodworms, and they do like the cichlid flake and hikari bio-gold. Still won't eat NLS pellets unless I crush them first.

I added more plants-

this bit of anubias just drifted up during water change and got stuck in the pothos roots, I thought it was funny so I left it there

I took all the java ferns out of my other tanks and moved them in here. Look nicer already, while the narrow anubias are starting to turn yellow. Maybe I will have to reduce to fewer plant species, the ones that do okay (buces).

I took windelov ferns off the clay arch in the 33, re-tied onto a stone and wedged into a crevice in the driftwood. Curious to see if it prefers this tank just like the java ferns appear to.

And the last change was with sponges. Read in some reviews that the older style Hydro sponge, gray with finer pores, actually holds more of the mulm in it, while it kind of falls out of the newer, coarser black sponges (called 'pro' version). Yeah, mulm always scatters out when I pick them up for rinsing. Realized the Hydro I that I originally got for the betta tank, was that older type, and it's the same width as the two Hydro III's I already have in this tank. The fittings match, so I simply stacked the Hydro I ontop one of the coarse sponges. Want to see if it does hold more crud. I increased the flow through the filters, as well. I can't tell yet if the tank is staying cleaner-

if I do change out sponges (replacements are just a few dollars), and still have this problem with excess mulm even though I'm feeding less, I cleaned up the sticks and the leaves will soon be gone- I guess I'll have to ditch using sponges and put the canister filter on the tank. I don't want my angels to have more problems. Maybe I will find some fake stick decor, that won't break down. Or some tall plants instead.