The small nearly transparent squiggly ones sound like midge larvae, of which there are many kinds (I've heard "bloodworms" used to refer to a ton of different beasties, including one kind of midge larvae which is red, but midge larvae don't necessarily look anything like bloodworms.) I have some very similar to yours in my tank, about 5 mm, hard to see. The spirally figure-8 dance is characteristic. If you look REALLY close, see if you can see a slightly darker head at one end and a couple tiny bristles at the other, they're actually not as worm-like as they look at first glance, one end is slightly thicker.
Took me a while to identify these in my tank. The tip-off was the coincidental appearance of tiny green flies, like miniature mosquitos, here and there in the house. Not all are green. Most are small and resemble mosquitoes, but not many bite.
Most midge larvae, when not squiggling in the water, construct little snug-fitting tunnels made from some sort of silky material on rocks, wood, and sometimes the glass. Very hard to see if there is algae, as the tunnels match... they lie flat against surfaces and look like little raised lines 1-2 cm long. The larvae pokes out one end and scarfs down algae and debris.... they clean a little patch on whatever the tunnel is on. I'm sure mine have tunnels in the gravel but are impossible to see. Easy to see on some of my rocks, though, and there are some on the driftwood.
They are totally harmless, and since they are eating very minute particles of algae and detritus it doesn't mean your tank is dirty, just normal
. Fish will eat the free-swimming ones. I am going to experiment with moving some kuhlis into my infested tank to see if they will clean up the ones in the tunnels.
Eventually they pupate inside the tunnel, come out and make it to the surface, where they fly off. My infestation started in an open-top tank where I noticed the flies hanging around. I have tried reducing mulm, debris, algae, etc. and they are still there, so it may be something that has to run its course. I'm not sure how long they remain as larvae.
Does that help (or does that sound like them?) They are NOT parasites of fish in any way. I will let you know how my colony progresses
Took me a while to identify these in my tank. The tip-off was the coincidental appearance of tiny green flies, like miniature mosquitos, here and there in the house. Not all are green. Most are small and resemble mosquitoes, but not many bite.
Most midge larvae, when not squiggling in the water, construct little snug-fitting tunnels made from some sort of silky material on rocks, wood, and sometimes the glass. Very hard to see if there is algae, as the tunnels match... they lie flat against surfaces and look like little raised lines 1-2 cm long. The larvae pokes out one end and scarfs down algae and debris.... they clean a little patch on whatever the tunnel is on. I'm sure mine have tunnels in the gravel but are impossible to see. Easy to see on some of my rocks, though, and there are some on the driftwood.
They are totally harmless, and since they are eating very minute particles of algae and detritus it doesn't mean your tank is dirty, just normal
. Fish will eat the free-swimming ones. I am going to experiment with moving some kuhlis into my infested tank to see if they will clean up the ones in the tunnels.Eventually they pupate inside the tunnel, come out and make it to the surface, where they fly off. My infestation started in an open-top tank where I noticed the flies hanging around. I have tried reducing mulm, debris, algae, etc. and they are still there, so it may be something that has to run its course. I'm not sure how long they remain as larvae.
Does that help (or does that sound like them?) They are NOT parasites of fish in any way. I will let you know how my colony progresses
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