Triggering BN Spawning Activity

I have a question which i have tried to confirm the answer to by reading and searching online. However i have run into some contradiction (i was as suprised as you all, i mean contradiction in fishkeeping!!!!).

I have read that cool water changes are a good start, its the temperature is my question. Is there a magic number or a rule which says for example 4 degrees lower than the usual temp?. Or is it a case of trial and error and seeing what works best with your particular pair of BN. Mine are commons (still not sure of the L number as i have the L number aqualog but nothing seems spot on?).

I am planning to move my BN's to their own tank as they are in a community tank at present which is far from ideal so am eager to give BN breeding a proper go.

there is no magic number that i use. My tanks are at 26 degrees C and i do a 30% water change using water straight from the cold tap. at a guess it would drop down to about 22 degrees. Usually drops the temp for a few hours and i do it in the evening as most of the magic in my tanks seems to happen at night, not all but most

Have you followed all the steps leading up to trying to trigger the spawn? I ask becasue if they are not ready to spawn then trying to trigger it will only annoy them and result in either frustration on your part, small spawns or booted eggs. all of which we try to avoid.

giving them their own tank is def a good idea as some community fish dont deal well with cool water changes

oh, and common bristlenose dont have an L number. they were already well established in the aquarium trade before the L number system came along. some of the rare ones do, but not the common ones

As always Doug you have given me some great info. I havent really seriously tried to breed them other than ensuring I have a male and female.

I will certainly look at the seperate tank option. Looking at a 4ft 240l tank and hoping to have my current pair of BN's and possible a trio or pair of longfin albinos. Just in case your interested this is the tank setup i am considering as an option http://www.seapets.co.uk/products/aquarium-supplies/aquariums/fluval/fluval-roma-aquariums/fluval-roma-240-aquarium-and-free-cabinet-black-titanium-and-zebrano.html


My community tank has rams, clown loaches various corys, danios etc so i'm sure the BN's are never relaxed enouugh to spawn, or if they are the eggs or lavae dont stand a chance and my community tank although littered with wooden caves, slate breeding caves, mopani wood, plants etc if is situated near a high traffic are in the house. My new tank will be tucked away off the beaten track so it should not be too noisy.


I do also have 3 clown plecs but they are still very small i was hoping that they might spawn and more by luck than judgement i have 2 females and a male but like i said they are small (well 2 inches).

Thanks again Doug

No worries, glad to help

I would suggest that they would never breed succefully in the community tank for one reason...Clown Loaches!!

Clown loaches are skilled egg hunters and are armed with the weapons to give even a big male bristlenose a nasty injury. I have heard of many a death caused by bristlenose vs. cloan loach cave fights. never good

Also, 240 is a big breeding tank mine are about 60 ltrs. Im sure the fish will love it but if all you plan to do is breed in it then its a bit of an overkill. I would save the coin and just get a smaller tank.

mine are 60lt too Doug. Just need something to grow the fry on in as well

Grow out tanks are for when you get serious about breeding. If you just have one pair then you can normally get away with the babies staying at home with mum and dad til thye are ready to move out