The summer season isn't under way yet, but already there are concerns about the algae levels in the popular Geist Reservoir.Environmental experts told city leaders at a summit on water safety Friday that algae levels in Geist are the highest in the area so far, 6News' Ericka Flye reported.Researchers said the algae in the reservoir has been a growing problem, in part because some area homeowners over fertilize or use fertilizers containing phosphorus, which acts as a source of food for the algae.The phosphorous runoff can flow directly into the groundwater. The same situation led to a water advisory at the reservoir in 2007, when unsafe levels of blue-green algae were found."The algal population at Geist Reservoir right now are pretty high. They're above the world health standard for moderate risk for recreational exposure," said Dr. Lenore Tedesco. "For the common person that means they need to be smart and use common sense if they're going to recreate in the water."Experts recommend that those who touch the water wash it off when they're done and try not to ingest it. Hamilton County homeowners have also been asked to cut back on using fertilizers.Ken and Joni Kelly are looking forward to taking their boat out on Geist, but said they'll be extra careful with the water warning."You hate to spend all this money and not enjoy the lake, so we definitely want to be able to use it," Joni Kelly said. "We'll use it and then we'll take a shower."Experts said the warning is not meant to scare people away from the water, just to help them enjoy it safely."Well, having three young boys we'll probably still end up going in the water," said Julie Vandenbark. "We'll just be a little bit more cautious about cleaning them up."