I ended up buying four of them in total, and they were one and a half inch at most). First one regular color and one albino. Then they died in less than a week. The substrate in the 30 gallon aquarium where they were had white rock substrate(but not polished small pebbles). I noticed them when dying having little blood under their bellies. So the next two I got were again one regular, and one albino.
These bristlenose plecos went into the 60 gallon tank with polished pebble. Happy there they went and couple of days latter the regular color pleco showed up dead. I said to myself that if the last pleco died I would not get any more plecos. But the only bristlenose plecostomus survivor(and albino by the way)is growing and seems to be doing just fine.
Plecos need either sand substrate, or polished pebble so they don’t cut their soft belly.