Hi there
I also live in the UK. I have recently had a berried female red claw. Female was only 4".
It took about 30 days for the eggs to hatch and a couple more weeks to detach from her. I could see the baby crayfish moving on her a couple of weeks before they started dropping. All you see is black eyes and little white antenna moving.
I left the babies with the mother for a few days but noticed that there were only half attached compared to what there was. I thought she had eaten them but i found about 150 dead babies in the filter about 4 days later so make sure you check the filter or cover to prevent them getting in. They are good climbers even when small.
I took mine at a 3 or 4 days old and placed them into two material breeding nets with loads of plants. The plants help stop the babies cannibalizing each other. Try not to handle them or be careful as they are very delicate. I siphoned them up and held a net under the outlet, i then transferred them to the breeding net.
I left about 10 in the tank with the mother; they had made little homes between the bogwood and gravel so i left them. After a few weeks i noticed that the ones that were left in the tank were growing very quickly and most had kept out of the way of the fish in the tank. The ones in the basket were only growing half as fast.
I decided then to let another 10-15 from one of the nets out into my other tanks. They started to grow a lot quicker than the ones in the other breeder net and most seemed to be doing well avoiding the fish. I have now let the other 20 out into various tanks.
Here is mum and dad
Here is a picture of babies at about 1 week old.
Here are a couple of pictures of the babies in various tanks. About 2 months old. I found small pieces of lava rock and broken up pieces of pottery served them very well. The lobsters rearranged the pieces to make their own homes. They love bogwood and Im sure they get some of the nutrients they need from eating the wood.
The will eat normal fish flakes and will break off small pieces of algae tablets when they are very small. I found 'Tetra Variety Wafers' were great as they are for bottom feeding fish and crustaceans. I bought them off of eBay quite cheap. They love small earth worms, bloodworms, and small pieces of meat, anything that the adult red claw will eat.
One other thing i did was add calcium to some tanks and they seemed to grow and moult faster than those in the tanks that did not receive extra calcium.
This is just my own experiences but hopefully it will help you and the babies.
Tracy