[Tee]

Hi all, I'm having trouble with my large mushrooms. I started with one about 6 years ago and it multiplied very quickly. The mature ones measured over 3" across. In the last couple of months all of the little (new) mushrooms fail to grow. Now I don't have any over the size of a dime. I have lots of them but they just aren't growing. They're coming off their rocks as soon as they get to the dime size. I change the bulbs in my lights about every three months. They're normal output. I have a low to moderate water flow. My skimmer is an AquaC Remora that's pulling a good amount of skimmate. My set up has changed very little in the past 8 years, I always having success with the shrooms til now. My frilly mushrooms are still growing.
I feed the tank DT's and a good mixture of frozen foods. Does anyone have ideas what the problem could be? I really miss seeing those huge mushrooms I used to have.
Thanks
My perameters are:
temp: 78oF
sg: 1.027
Ca: 440
alk/KH:100mg/L (I use a nutrafin test, the idea according to it is 105
pH: 8.2
Nitrate: 5.0
iodide:.05