Red Eared Slider laying eggs

Question
Last Saturday I was surprised to find an egg in my turtle's tank...it was about the size of a grape.  There was only one  and some white slimy stuff in the water too.  I was really shocked!  She is 15 years old and this is the first time since I've had her 7 and a half years...that she has laid an egg.  She has never been mixed with any other turtle so I was guessing thatthe egg was a dud.  I removed it and cleaned the tank. I still have it.  Twice since then I have notices the same white slimy material floating in the water and the water will cloud up a lot more sudden after cleaning it.  Can you help me out...is this normal????  Is it possible that she is having eggs and eating them?  Really curious as to what is going on with her!  She is very healthy and nothing has changed with er.  I would appreciate an answer if you can give me one..;)  Anne

Answer
Older females often lay a few infertile eggs- apparently they use this to get rid of stored chemicals, calcium, hormones, etc. These eggs are almost never fertile.

The white stuff is probably just organic material she is expelling that the bacteria in the tank are feasting on, or stuff that is changing the chemical composition of the water.

If the 'bloom' occurs again, i would change a lot of the water and think about overhauling the filter.