ACF tad - second mass die off

I have bred ACF for a few years, I am used to having the odd batch of eggs fail and go moldy but my last two batches of eggs have suffered a 90% plus die off within a week or so of hatching. I will give you the care methods I have successfully used in the past and some information on the frogs I breed and hopefully I can get some useful advice. I have three females frogs who have ben laying, a three year old female albino ("pinky") who has successfully laid in the past and two of her daughters from early last year, they are golden reticulated and were selected for their markings, my two males are golden with a slight reticulation they are the father/s. When I think my females are getting ready to lay I sterilize my plastic plants with boiling water and some salt, rinse then dump them in the frog tank, I repeat this daily till they lay. Once I see eggs, I remove the plants and place them in a separate tank with light aeration and a heater set at 24c. When they hatch I feed liquidized spinach with some spirulina . They morph at around ten weeks , end of story, a few deaths but overall a very high survival rate 95% or so I imagine. This was until my last two batches. My first die off occurred a couple of months ago, I pulled the eggs from the tank , all three females appeared to have laid, it was a first batch for the two youngest females, eggs were scattered every where, I removed the plants with the eggs on to a separate tank left the rest in the adult tank and they went moldy. I had about 500 eggs, they hatched fine , within a week I noticed the tads were dying off fast, fifty a day minimum, within a week of this I was down to fifty. They showed no physical signs of illness or damage, death was however proceeded by the tads twirling about in a corkscrew motion, I see this in every batch but only in the odd individual. I put the die off down to the sand I had left in the tank, I had salted the tank and put the temp up to 35c for a week to sterilize it , then done a full water change, I thought some salt had remained in the sand , once I removed it the die offs stopped the next day. I had also considered chemical contamination of the spinach and had changed the brand, chemicals such as deodorants and air fresheners are banned in my tank room. My second die off has just occurred, I am using an 80 liter tub, no sand, care requirements as previously stated. One week after hatching about 350 tads I am down to thirty in two days. It doesn't appear that the sand was to blame, something else is happening and I dont know what. Any help and advice I can get would be much appreciated. Sorry for such a long post.

Could it be a contaminant in your water supply? I assume you must do frequent water changes with your tadpoles and use a dechlorinator? Maybe your council has added something new to the water supply and the tadpoles are more at risk then the rest of your aquatic pets. I know straight away if I've forgotten to add dechlorinator to the water of my baby axolotls as they do the same cockscrew swimming you describe. I guess a pesticide on your Spinach could have a similar effect? Hope you find out what's causing this soon?


Regards Neil

I do a water change every two to three days before a feed and use a dechlorinator without fail. I did consider chemical contamination of the food which was why I changed the brand of spinach the first time I had a die off, the second time I had no opportunity as it occured between feeds.

All three of my females laid over the space of a week, I upped my water changes to 50% daily, I have had no major die offs just the odd tad. I have about 1000 atm and they are a couple of weeks old and doing well. I think the problem was probably lack of care, I was used to having a few hundred tads at anyone time , the higher number obviously required higher water changes. I feel a bit stupid but a good lesson was learned.