Stringy Poo

A few questions if you don't mind.

How long have you had the rainbows?
Did they all start stringy poo at the same time?
What colour is the poo? (yes I know  )


It would be unusual for a whole shoal of fish to come down with some infection/infestation at the same time if you have had them a while. If it's only been a few weeks to a couple of months then it could take that long for something to show up. Longer than that it shouldn't be anything they had when they arrived in your tank. And an infection brought in by a more recent fish shouldn't affect all the rainbows simultaneously.

If you've had them more than a couple of months and the stringy poo affected them all at the same time, diet seems the most likely cause.

In that case, I don't suspect any disease unless the bristlenose or any other fish are also showing symptoms.

And just because you haven't seen it, it doesn't mean they are not eating the BN's algae tablets.

I wouldn't have thought plec pellets would do this but I'm at a loss for any other ideas.

WR has had the rainbows for 2 years so it is very unlikely to be anything they came with in terms of internal infections or parasites. The only other thing I can think of is that a more recent addition (ie within the last 2 or 3 months) has brought something into the tank, but that fish would also be showing symptoms. But he doesn't report anything but the rainbows being affected. And all the rainbows became afflicted with stringy poo at the same time.
The only thing WR reports that has changed is that he's bought a BN plec and has started feeding algae wafers for the plec.

Most commercial fish food is roughly the same regarding nutrients. Some pellets designed for cichlids are on the meaty side, and some other food is more veg orientated but that's all. The main difference between foods is how it behaves in water - flakes float, pellets sink. Your rainbows will be fine eating the cories pellets - as long as the cories don't starve!