The water in my viv is constantly turning a very noticeable yellow, however the water isn't murky.
I do have a piece of red driftwood in the water, and I was told it may change the colour, but it won't harm the frogs. However, both toads refuse to go into the deeper water (Which is yellow), once it changes. I do a partial water change every 3 days or so, but after only a day, the water changes yellow again.
I thought it may have been my filter, so I took it out and let it run through clean water for a couple hours. The water did not change colour, so I'm assuming that's not the issue.
I notice when the water is clear, both Hugo and Hermes enjoy swimming around in it, and Hugo changes a couple shades lighter. But as soon as the water changes, both Hugo and Hermes turn almost black in colour, and stay on the land portion. They won't even go on the floating dock that is located over the deeper water.
I've been told both toads may be stressed, but I have left them be for a few days and with no change. Sadly, they are in a fairly high traffic area on weekends, but during the week they are very rarely bothered. I have absolutely NO area that these guys could go, other than where they are now (I live in a very small home, and only a portion of that is actually mine).
I am planning on getting a UV light to help get their colour back up, but I'm thinking there may be some other factor.
Maybe the yellowing water is more than just my driftwood?
I'm going to be picking up some PH sticks from a local Walmart tonight after work. But I don't see how Natural Bottled Spring water could have an unusual PH balance, even with the driftwood in the water.