Hi Gianne,
Welcome to the forum. Nice to hear you have your tweediei from Lawrence Kent – I agree, they are very beautiful, as you have said. Your experience with keeping and breeding wild bettas will go a long way with keeping and breeding your tweediei. As the more experienced breeders have already commented, keep a close eye on your water conditions, especially conductivity. I was only able to get viable larvae with a conductivity of 50 µS or lower. However with your rainwater showing a reading of 8 TDS (or perhaps ~16 µS), you are well below that. I think it was commented that one does not want to go too low on TDS/conductivity, maybe a bit higher say 15- 20 TDS (30-40 µS) might be better? I’m not sure positively sure of that, maybe others can comment on those values.
I have some F1 tweediei from Lawrence as well, you can see some photos of them here. I think there may have been a first spawn from them, as one of the males has been missing from feeding time and occasionally seen chasing other siblings away from his cave under some leaves. I will separate the two males with a female each in separate spaces for future breeding.
Good luck with yours and if you are handy with a camera, please post photos if you get the chance! BTW, thanks for including the link to your website, very nice!
David