You've had a couple of things happen which didn't happen to me:
1) you had a rapid disappearance of algae following initial stocking of Tilapia...and during a temp period which, as I recall, was not conducive to Tilapia feeding.
2) you've had the algae come back as bad or almost as bad as before Tilapia stocking.
Here's my guess, Ryan, and I underline guess as to what may have happened:
The first occurrance was an act of nature...either temp change, rain or some combo knocked the surface algae down but not nearly out, on the bottom of the pond...and that was not due to the effects of Tilapia. By artificially feeding Tilapia in the early season, you delayed or lessoned their effect on the algae.
Now that your temps are up and artificial feeding is limited(the eighties are great for Tilapia), they are working their magic on the bottom residing algae. It took me a full growing season the first year to see complete algae control. The second season I used early season treatments of cutrine plus to help with control before the Tilapia were "unloosed". The third season and subsequent have been completely chemical free and algae free....this has made me suspect, certainly not prove conclusively, that there is a cumulative effect from Tilapia relative to algae control.
What to do now? I think that's entirely your preference/call. My experience says, if you are patient, the Tilapia will reduce/eliminate the algae as the season progresses....and it will get better with each passing season.
You could treat with chemicals if you want more immediate results. A word of caution, however, regarding use of chemicals in the full summer temps...use sparingly and only on partial areas of the pond, in order to lesson the risks of DO problems.
Bottom line from my experience....be patient. Hopefully you will report down the line, like Looptech did recently, that the Tilapia have worked their magic. Good luck.
