stanny,
my BN aren't really that bothered which way their cave / shell (in my case) is facing...
they seem to breed no matter what.....
I have tried caves, small plant pots, ornaments, and now spine shells.. and I can say that mine seem to prefer the spine shells as they have a over hang and the fish see to find it easier to keep others out and be able to protect their young easier...
cant be doing much wrong as now on 3 spwan with this pair and have about 120 small pleco's in the tank right now.... just need to find a local LFS in Rotherham or near to Sheffield / Barnsley to take some off me...
I def dont use a power head... just as gee man says- regular water changes evry day, sometimes I can not fit every day in but will get up early the next day and do a water change in that tank real early...
I also have sand substrate which I think is more natural for the fish and pleco's I could be wrong but it is a learning curve some what always..... I do try to keep a couple of corys in the tank to stimulate the sand as they like to rough and move the sand about... though for some reason cories don't like this are of yorkshire coz I have lost some recently....
was thinking of contacting the water board to ask them what is in the water right now...
or when I return to work having a HMA fitted sooon....
my males hardly ever fight, they sometimes flare at each other over algae wafers but both my males take it in turn to fan the fry in the luv shack shell...lol
good luck LJ