The tank has a very different feel with just serpae tetras and kuhlis.... the serpaes are starting to figure out that when I lift the lid it's not reason to hide, but might be food. I have started feeding them more fresh foods- greens and insects- lettuce and dandelion leaves both were gobbled up. They have eaten small moths, tiny caterpillars and aphids from my house and yard. The moths and caterpillars I freeze for later use, the aphids I chill a few hours in the fridge then feed same day so still very fresh. To gather those I dip the rosebud end in a bowl of tank water and swish it (carefully, to not break the bud off). It was so effective when I checked a few days later, couldn't find very many aphids so refrained from gathering. Maybe in a few more days.
Caterpillar-picking is very effective too. First time I got at least twenty, thirty caterpillars. Second time I only found four. Then just six- and there were some teensy ones I actually left to grow bigger (would have squished them if I tried to pluck off the leaf). Also in the garden beds I got aphids off of leaves by turned their undersides up and wiping with a wet finger, then dipping it into the bowl of tank water. Got lots of aphids and a few other tiny bugs this way. There were plenty to get off the tomatoes and swiss chard leaves, but what really staggered me was the swarms all over underside of borage leaves- the biggest, two-year-old plant. Surprised me because the plant doesn't seem to be suffering at all, it doesn't have pale spots or anemic-looking foliage. I get some tiny flies, minute brown round beetles and other bugs I don't know, but it's mostly aphids. I make sure to leave alone the spiders and ants. Saw a very pale, light green bug with incredibly long antennae- the wings were too faint to distinguish but I think this one might be lacewing so left that alone, too.
It can be funny feeding the fishes aphids. The cherry barbs go quick after them. Serpae tetras were more hesitant, then enthusiastic when had a taste. They'd often spit one out and then snap at it again. One tetra grabbed at a clump of aphids and a few must have still been alive- one crawled up on its head, just above the mouth. The fish jerked around and managed to get it but sure was funny a moment seeing fish swim around with a bug meal on its face!
A few of the aphids were missed and sunk to the substrate- kuhlis blazed past them, going nuts searching for the food they were sure I'd put in the tank when heard the lid open. Later when I checked (don't want missing insects rotting in the tank no matter how small) couldn't see the ones that had fallen. I'm not sure if the tetras found it, or if the kuhlis ate some. I'm sure a shrimp would if it got ahold of it. Really was curious to see if the kuhlis would- I know they love bloodworms when they can get them, and I've seen one choke down a tiny caterpillar before.
Yes, some aphids have wings. The ones I saw are aphids, not lacewing. And some can be aquatic- crawl down stems to feed on plants underwater. So I only give in small pinches to make sure the fish eat them all, or chill them in the fridge long enough to stop life.
All my kuhlis are positively pudgy now from the lack of competition on the ground- except for Sassy. I'm going to do a levamisole treatment later this week after all...
I really like preparing greens and catching bugs for my fishes. Not about saving money- a $10 container of commercial food lasts them all for over a year anyway- but it just feels satisfying and they sure love it. Between the peas, lettuce, dandelion, zucchini, moths, caterpillars, fruit flies and aphids- in the summer I may now only feed dried/prepared foods two or three times a week. Although I haven't had fruit flies in my kitchen for a while (something the rest of my family is glad of) but the little moths are kind of a new thing.
Swordtails really liked dandelion greens, by the way. They didn't spit any out as with the lettuce leaf, but gobbled it down. Only now I have to spot-feed the swordtails. The cherry barbs are just to quick for them. I feed a bit to garner interest, then wait for the swordtails to come to the surface, and have to drop a large clump of food right in front of their face so they can get some while the barbs dash in. Incompatibility doesn't just have to do with aggression [sigh]. It's also about food competition...