Well first off I suggest you pay closer attention to the water quality. A strain of fungus seems to be one of the leading causes in captive deaths of these guys (hence keeping them at a lower ph as this seems to deter fungal growths). Secondly 6 gallons is awfully small for 3 of these and doing 95% water changes will hurt you in the long run. Also make sure you are washing that whisper sponge out with water from the tank. Washing it with clean water kills all the beneficial bacteria on it. Please rethink the use of R.O. water as they seem to be able to "feel" the mineral content of water. The constant use of R.O. water would simulate a constant rainy season for them and hence breeding season. This could be possibly stressful.
Also keeping that knife in there isnt doing it any favors. It is most likely very stressed from the tiny living conditions and competing with caecilians for hiding spaces. Not to mention all species of knifes produce electrical fields to navigate the water and this could be detrimental to the caecilians. Plus they will eat it. Just give them time. These buggers eat everything.
Good luck with them. They are amazing animals to watch and one of my favorite pets.
As a final note, while many in early years most likely did die due to poor husbandry this was not the reason for the close of exportation. The country of origin simply stopped all exportation of non-fish wildlife. This is why some caecilians still make it into the market place as they are often misidentified as eels or worms by importers (this is how I fnally got mine after years of waiting and watching and at the price I bought them for these are not "blackmarket animals"
. T. Natans seem to be doing quite well in the wild due to fishermen gutting and cleaning their catch on docks and tossing the remnants in the water.
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0.0.1 Herpele multiplicata
0.0.1 Tylototriton shangjing
0.0.6 Typhlonectes natans
1.2.0 Anery Sand Boas
1.2.0 Emerald Tree Boas
0.0.2 Bufo Americanus
0.1.0 Red Tail Boa
1.0.0 Vietnamese Red Legged Centipede
1.0.0 Black Rough neck Monitor
