Dying SPS frags

[robbyville]

Hi Jason,

thanks for the thoughts. The frags were purchased at J&L, they were in their SPS tanks which I believe are illuminated with 400w (not sure if they have one bulb per tank or two). That is why I originally mounted it so high up in the system since I only have 250w bulbs.

I have not measured TDS as I do not have a meter. I think it's time that I get one though, I think I saw a special at J&L's. I wonder if it's also time to change the filters in my RO/DI, one of them is starting to get a slight yellow tinge to it.

Can you tell me what RTN stands for?

Thanks

Rob