I bought some play sand from Lowes today in intention of using it as substrate. I had rinsed it throughly in a bucket before adding it to a nearly empty 20 G tank. Once carefully adding the water to the appropriate level there was quite a bit of debris. Currently my frogs are not in the tank and are in a smaller tank until things get adjusted. Are there any ways to clear this up?

I had also bought API root tabs, but did not notice it was "plus iron." Do these cause any harm to the frogs?

I tried to look around online and found no answers.