worms and babies

Ok, so the goldfish are gone (relocated), so I only have my bristlenoses, danios and apple snails left.

All seems happy in there ... but, yesterday I noticed a tiny, almost invisible danio baby. This is what happened ..."QUICK, quick, a fish baby ... look! ... oh, the big one ate it".

Today I thought I had better do a water change and clean out a mucky and tricky to get to corner of the tank with the gravel vacuum, and siphoned the water into a bowl, so that I could check for baby danios that hadn't yet been eaten. As the muck settled, the whole lot seemed to be moving - it was full of small worms, about the thickness of a hair.

Presumably they are harmless as I haven't seen any near/on the fish, or any ill effects, but just wondered if anyone knows what they are?

Anyway, felt guilty about tipping them down the sink, so now they are in the stick insects' old plastic tank, taking up room on my table. I just checked on them and discovered a tiny danio clinging to the side.

So now I'm in one of my dilemmas - if I don't do water changes and gravel cleaning then everyone's health will suffer, but if I do, then worms and fish babies will get sucked up and killed. What do other people do? Do I just have to accept that I can't avoid killing them and try not to look too closely when I throw the water away? Otherwise I can see a nightmare scenario developing, where my kitchen becomes full of buckets of dirty water that I'm too scared to throw away.

Of course now the baby danio(s) and worms are in an unheated, unfiltered tank of still water, so I'm not sure that they'll do too well in there either! The danio is so tiny I doubt that I could catch it, and if I put it back in the tank it will probably be eaten as soon as it hits the water (like my poor water hoglouse was!)

Any words of advice?

They sound like they are either Detrius worms or Planaria.


Detritus Worms are normally not a problem and often go un-noticed living in the gravel aiding in breakdown of wastes. When the population explodes these worms often leave the gravel and cling to the sides, usually close to the surface as oxygen depletion due to the cumulative affects of increased organic mulm, cloudy water and simply too many Detritus worms drives them from the oxygen poor gravel.
The population explodes generally due to high amounts of decomposing organic mulm (often resulting in cloudy water, pH drops, etc.), which is often an indicator of a tank with poor filtration or poor cleaning practices.


Planaria are often found in aquariums with uneaten food. The planaria won't hurt the fish, but they are a symptom of too much gravel containing too much uneaten food, and that is not good for fish. They require a food source, which means there must be excess food wastes in the tank to support them.

get a loach in there, borrow one from the LFS and it will sort them out quick smart.

Thanks, they look more like the thin stringy ones, not the purple fat ones. No movement from them in the spare tank today so I guess maybe the drop in temp killed them, or lack of oxygen, or the shock of being siphoned up maybe. No sign of the danio baby either, unsuprisingly.

I don't mind the worms being there if they do no harm. The water looks ok, and the ph is fine, but I would like to lower the nitrate level a bit so need to do more cleaning out more often.

I would love a loach but I thought they weren't a good idea with BNs as don't they compete with each other for food and territory? I'm sure I have been told that one of them will feed off the other's slime coat (I forget which way round it was now). I have a pretty high density of BNs at the moment, 3 are coming up to almost full grown female size, but the others are still small. I'll have to start looking for new homes for them soon I think.