LoopTech,
A couple of questions on your situation and then a friendly neighbor question.
Is this the first year with Tilapia?
The reason I ask is that in my experience, it takes a good part of the summer for them to get ahead of an algae infestation in the first year. In my own case, in my first and second years with Tilapia, I found it beneficial to use Cutrine Plus in the early spring before Tilapia stocking to help the Tilapia "get on top of" the algae. Since those early years, however, I haven't had to use chemicals.
Second question....are you artificially feeding fish in that pond?
Artificial feed, according to SRAC and my own experience, can reduce the amount of natural food (i.e. algae) consumption by Tilapia by 50 to 70 %. I have definitely seen at least a 50% reduction in efficiency in a pond(mine) artificially fed. In addition, to reducing the Tilapia's effectiveness, artificial feed can increase nutrients which feeds the algae further. Before someone screams, I'm not putting down artificial feeding, in this case, simply stating some effects it can have on Tilapia effectiveness.
A comment, our very hot dry weather enhances algae production. Part of that is due to having the same amount of nutrients available in a smaller amont of water, i.e. raising the overall % of nutrients available to FA. Also, for some reason, FA disappears in my ponds after a good rain....which we don't seem to have any of lately. I'm sure the pros can give other reasons as well but hot dry weather seems to encourage algae production.
Like anything else, no one is saying (certainly not me) that Tilapia are 100% guranteed to cure all your problems. However, if you set up good conditions for their success, your individual probability of success improves. My own experiences with Tilapia, IMO, have been substantially improved, by not just throwing them in the pond, but by taking some steps to help them be successful. They have paid me back many fold, and I highly recommend them. I will say to anyone that Tilapia represent the best pond management tool available to pond meisters today.
I noticed you are into ranching and in East Texas. Wondering how your grass is doing and how hay production is shaping up for this year? I'm very concerned about getting adequate hay production this year.