i was feeding the fish purina fish chow for most of the year. $15 for 50 lbs at feed mill. i bought some food (almost double in price) like aqua max , brown , high protien , i think its 44 and high fat too. when i put the food in the water , i get like a heavy oil that stays floating on the water. you can see it coming off the pellets. is this putting nutrients in my water , the oil. thank you

As I recall from my organic chemistry, (could not find my organic chem book) most fats and oils contain little if any nitrogen or phosphorus. Most fats are composed of fatty acids (carbon hydrogen & oxygen). The oil from the pellets has calories but probably little plant nutrient value (nitrogen and phosphorus). Higher quality blend of Aquamax (bluebag) is 41% protein and 12% fat. Amount of oil that comes off the pellets varies with each batch of pellets depending on ingredients used each time; it does vary depending on availability of products at the mfg mill. Since the fish food contains higher amounts of protein it could result in a few more nutrients (from manure) getting into the water. But supposedly, higher quality feeds are more digestable by the fish and less waste and undigestable material is produced by the fish than with cheaper feeds. Did I answer your question?

The oil doesn't hurt your pond.

Also numerous oils are released naturally from decay of plant and animal materials. Often one will see small oil droplets or film appearing on the surface water that overlies organic deposits.

thanks Bill and Bob. it seems since i started using the food , in the morning when i go feed the fish theres little pin size brown specs on the water surface. i was just wondering if the oil was causing a zooplankton bloom during the day and their dying at night. if thats what the specs are. i'm guessing it is cause the small fatheads are very dark in the center. like there eating good. i guess it's not the oil. :rolleyes:

Brown specks on the surface in the morning could be one of many different things. Theywould need to be examined closely to get a better idea of what they might be. They could be cast skins from emerged insect larvae such as midges or less than 1/4" long mayflies; doubtful they are dead zooplankters which usually sink when they die. Maybe take some of them out. put them in a shallow dish with water and lok at them with a magnfying glass. See it they have any noticable structures such as appendages of legs, antennae or tails.