Day 18
Due to the terrible quality of my tap water (0.5 ppm ammonia, 0 ppm GH and KH), it's necessary to regularly test for not only ammonia but water hardness as well. Thus far I've been testing every two days. With the test today revealing a slight increase in ammonia levels, I'll be raising it to every day until I'm confident the water's been stabilized. As a precaution, I've added more Seachem Prime (a wonderful product that binds ammonia, nitrite, and nitrate) and will up the water changes to 50% (2 gallons) until the level begins to drop. The water hardness is staying stable thanks to my adding of around 4g of Epsom salt and 2g of baking soda each 1.5 gallon water change. I'll be cleaning the 20 gallon tomorrow when I get home and should be ready to set it up the next day if necessary.
If the ammonia levels continue to rise even with 2 gallons being removed, then I'll have to move the tadpoles into the 20 gallon sooner than I was hoping. As the tadpoles age, their bioload (waste production) will only increase, especially once they require more feeding to compensate for the increased energy that will be expended as they begin to develop their back legs. At worst, it simply means I'll have to move them into the 20 gallon tank by the day after tomorrow.
On a more positive note, tadpoles have now entered what I like to refer to as the Fu Manchu, where all of the tadpoles look like they have little mustaches. Aside from being quite fetching, the whiskers help them to interact with their environment through increased sensory input. For the more technically inclined, this would be Nieuwkoop and Faber stage 51, the tadpoles are progressing right on schedule. At this point, you can see internal organ development is continuing and each of them are becoming more defined. Every tadpole is still alive and outside of the two malformed ones, each seems perfectly healthy.