The summer months are probably the most active for both the fish and the pond owner.

FEEDING:
There should be plenty of natural insect life in the pond now. Fish prefer live food and may have less appetite for pellets.

INSECTS / DISEASE:
Watch out for beetles on the water lily leaves - if you see that the leaves are being eaten, spray them vigorously with a jet from the hose which will dislodge the beetles into the water so that the fish can eat them.
If the pond requires treatment for an algal problem, ensure the dead algae is removed as if allowed to decay in the water, this can lead to serious pollution problems causing disease to the fish and unhealthy plants. Consider fitting a UVC into your filtration system.
Beware of insecticidal spray drift from spraying operations around the garden. If insecticide gets into the pond it could kill the fish or upset the pool balance.

FOUNTAINS, WATERFALLS AND WATER QUALITY:
When adding a fountain, be sure to move the water lilies so that they are not under the spray of water - the flowers will not open if they are being 'rained' upon.
Most pond fish will spawn in the summer months, which can cause some problems with the water quality as the fish that are not spawning themselves will actively feed on the eggs. If the fish do spawn, monitor the water afterwards, particularly for the presence of ammonia and nitrite.

PLANTS:
Even the late aquatic plants, such as pontederias and arrowheads will be available by the end of the month.  Many plants will be flowering - trim off dead flower heads and foliage which can look untidy. Irises should be divided and replanted after flowering if the clumps are getting too large.
Floating plants will help to give the fish shade: water chestnut is very attractive, and our native frogbit is ideal for small ponds.