Thanks for the advice

Using the LECA mostly to fill some volume so i dont have a mass amount of water as well as provide more surface area for filtration bacteria to attach to? When i placed the order for everything i figured id just tack it on to have just in case. lol

Have the water situation all worked out, been raising 4 tadpoles for about 6 weeks now. (finally starting to bud front legs) they will be transfered to a 5 gallon tank while the viv is under construction. The 5 gallon will then slowly be transformed into a planted aquarium