Bristlenose Pleco Breeding Issues

[ThatFishChick]

Hello everyone! So I just recently decided I wanted to try my hand at breeding BNs, and it seems I'm not doing so hot at playing match maker. I have a 20 gallon long tank,filled with super long plants and duckweed, very shady, I have a pretty long log that has a very cozy overhand and I have a breeding cave. The male I want to breed is a barely 3 inch long albino BN, and the female is a regular common BN pleco, and she is a good bit bigger than he is. I have had him in with another female that he was was greatly interested in, however she was not sexually mature and still very young, so I switched her out. There are six cherry shrimp there currently, just for the record, and the male kinda seems to ignore this female. She is very gravid with eggs and interested in breeding (she loves the little breeding cave I put in there) but unfortunately, the male is just not interested. Any ideas on how I can coax them along? DO you think he is scared of her? I'm including a picture of them side by side just so you guys can see the size difference.

pH= 6.8
Temp= 80 degrees
Alkalinity= almost 0 ppm
Nitrates= 20
Nitrites= 0
Ammonia= 0
Hardness= A bit on the hard side.

Anyway thank you guys for listening to my shenanigans!

 

[ThatFishChick]

UPDATE! So I suppose I forgot to mention the new female and the male have been together for a day so far. I had just recently gone to check on the two and the male seems have chosen his mating spot. He has created a ditch under the log and is now remaining under the log overhang with his head sticking out. I guess now it is a waiting game to see if she'll notice him. . .

 

[phyco]

you could always start feeding them blanched foods more regularly for a couple days then one day add 10 or so ice cubes and drop the temp by a few degrees to simulate rainfall, this usually triggers them to breed if not you'll just have to wait as only time will tell if they pair up.