Perfect Pair?

Any idea why my perfect parent raising Angels have just eaten their last two spawns???

I've had 4 or 5 successful spawns, but the last two got eaten after they moved the wrigglers?? No idea which fish was guilty.

There are lots of reasons why angels don't parent raise. Often it can boil down to security, if they feel vunerable or insecure they're likely to eat their eggs or young. So if they've only started egg eating since being moved to a new tank, that might be the issue. One of my first pairs were good parents, but would usually eat the first couple of spawns whenever they were moved to a different tank.
Another possible issue may be that the eggs/wrigglers aren't developing properly this can be down to diet, water quality (including temperature), or simply over spawning (each batch of eggs the female produces requires a considerable investment in nutrients, with regular spawning it's possible that the female could become deficient in one or more of these).
A further possible explanation, if the parents have remained in the same tank, is a build up of pathogens.

There are many other possible causes, but whatever the explanation, the solution is much the same :-

Move the pair either to separate tanks, or a community tank with lots of other fish, feed them up well on a good quality diet, and give them at least a month off. Before introducing them or any other pairs to the breeding tank. Bleach the tank using a peroxide bleach (Milton's baby bottle bleach is ideal). Leave for 48 hours, drain, refill, drain again, refill. Once up to temperature add a mature filter (I use air driven sponge filters with at least 2 sponges in each tank, that way if I need a mature filter after a strip down, I can pinch a mature sponge from one of the other tanks.) Leave for 24- 48 hours and check for ammonia & nitrite before adding any fish.

Although I don't always follow this procedure before adding a new pair to a breeding tank, I do always give the tank a good clean. If however I've had high mortalities, poor hatch rates, or an unsuccessful pairing, I usually bleach the tank. I've noticed that I usually get larger batches immediately after this process. In practice I'd rather have a batch of 100-200 babies than one of 500-600. But if I wanted larger batches, I'd be bleaching the breeding tanks more frequently!

Thanks for reminding me about using Milton or baby bottle sterilizer. I used to do this to clean out fry tanks but I ran out of it and started using Acriflavine. I will get some more Milton, Sainsburys do their own brand and its a lot cheaper. I have also used the baby bottle sterlizing tablets which are not dissimilar to the bleach tabs you get in the pound shop. I have disinfected nets and other equipment with them. You do need to rinse well, and I double dechlorinate too. I have wondered how I would get on using my steam cleaner to sterilize things.

I am yet to experience a pair of my angels which will parent raise the fry which is a little depressing. I have considered covering the tanks with black bags as I saw another breeder who had done that.

Thanks Rob some very good advice............ as usual