Don't forget the basics!

Read almost any book or article on fish breeding, especially one written in the 60's or 70's and it will almost certainly say something along the lines of, "Condition the parents by feeding copious quantities of live food." The thing is, scientific understanding of the dietary needs of fish has moved on a long way in the 60 years since Tetra introduced the first flake food way back in 1956. Production techniques have also greatly improved. One of the advantages of running a shop is that fish food manufacturers are so keen for you to feed their food to your fish that you're never short of free samples. Personally, with the exception of baby brine shrimp for fry, I'm leary of feeding live food because of the risks of introducing disease, pests & parasites. I do occasionally use frozen foods, which having been irradiated are disease free, but in general my angels have thrived and bred very successfully on an almost exclusive diet of Tetramin flakes.
Last year I won a photo competition and found myself the proud winner of a huge amount of fish food from a well known manufacturer, it seemed a shame to waste it, so, for the past 10 months or so, my fish have been happily feeding on this alternative brand.
Another thing that the books tell you is to pay attention to water quality. My local tap water is rather harder than ideal, so when I first started back breeding angels I regularly carted R.O. water from work, but this became a chore, instead I tried various techniques to soften the water, including adding peat to my water reservoir and adding a product made by Dennerle called TR7.

Over recent months I've had a lot going on and haven't managed to pay quite the same attention to my angels. When they have bred instead of 100's I've often ended up with half a dozen or so survivors. My one large batch in the last 3 months is a batch of silvers, generally these are the toughest, fastest growing, least problematic fish you could ever hope for, but this batch seemed to be struggling, slow growing, tatty fins, with the smaller ones falling regularly by the wayside. I treated them with all manner of chemicals with only limited success, and I was on the verge of blaming the parents when I realised, their heater wasn't working. I'd been fooled into complacency by the original LCD stick on thermometer which resolutely reads 82f irrespective of the actual temperature. I changed the heater and suddenly these poor pathetic specimens are thriving, fins recovering and growth suddenly where I'd expect it to be.

This made me stop and think, "What else was I taking for granted?", I suddenly realised that the decline in survival rate correlated with the change in diet, and with my stopping using TR7. So about 3 weeks ago I started using the TR7 in the breeding tanks, and feeding Tetramin to the breeders, I also checked all my other heaters were working properly. Yesterday I had two batches go free swimming, it may be co-incidence, but I'm pretty convinced that the change in diet in particular has done the trick!

So the moral of the story, don't become complacent, check the basics.

Very interesting Rob, I've been struggling this year too, I shall look at the basics again thank you

Just went to do a water change on a fry tank, it only had half a dozen in it fortunately, I was thinking to myself the water felt warm......... having been out in the garden I was blaming that.......... checked the temperature................. its 91!!!!!!

Heater is now in the bin!!! I'll let the poor things cool down slowly, just hope they survive

They should be fine, but I would drop the temperate over a couple of days, ie set the new heater to 86ish, then down to 82ish a couple of days later, and then tweek it back to 78/80 a day or so after that.