However, the risk of minimizing the waterflow, as I´m pumping water into the other tank, was very high – the receieving tank may overfill (that´s why there are 2 pipes, for safety).
So Itried to get the first one out by pushing another pipe toards him, but it was to short, and “caudi” refused to get out. The flow would easily flush out the loach, but it repeatedly went back into the pipe, so I decided to get the camera. The pipe by the way, even though original Eheim, did change to white color, on the outside, where in contact with water – so it´s only coated inside. That darker zones were the preferred places for the loaches.
Now the surprise, after carving some plugs, I felt quite safe, BUT next morning there were one Striata in EACH pipe

So, I learned from that and waterbridged another small tank to the “small-loach tank” with a 2” pipe. It was meant to contribute to their entertainment. Yes, it worked, sort of. Next day, there were 1 Y.Nigrolineata, 1 male Amana shrimp and 2 kuhlis in the added tank. But to my surprise, they did not find there way back. As I had the feeling, they were rather stressed, I guided one kuhli back through the pipe, which it seemed to avoid all the time. On the others I run out of patienece and caught them to return to their main home. I´ve put a plug on it now.
I may, some day repeat that for the big-loaches, to learn whether they have better orientation than the small ones and find there way back. I´ve bought a bunch of pipes to add a tank just with pipes and some plants.
In the long run, I will create a pipe-manifold and pump some water through, just for the loaches tro sleep and hide in, so they get what they seem to really need, to be even happier…
Almost makes one speculate as if they have some instinct, to enter pipe-outputs and avoid pipe-inputs, perhaps knowing, that coming back is easier when entering against the flow…

