Use a camera and camera tools that are suitable for filming in an environment in and around water.
Utilize underwater waterproof camera housing or a water proof marine case suitable for the specific type of camera you are using. Most major camera brands design these products for the specific make of the camera.
Determine the type of camera shots you need to take in or around the indoor pool and decide on the types of filming equipment needed for each shot and scene.
Get suitable equipment for underwater shots, such as underwater video lights, lens, filters, strobes, sync cables and ports.
Position the lighting equipment to film scenes with lighting placed at the right angles. The size of the lights will depend on the size of the indoor pool and the area round it; use larger lights for filming at a wide angle for areas around the indoor pool; use smaller lights for filming close-up shots for scenes focused on persons or objects. Do not video tape subjects with the light behind them.
Protect electrical cords and other equipment from getting wet when in use near the water. Exercise caution when moving camera equipment and crew around the poolside if it becomes wet and slippery.
Use a tripod if necessary to film scenes outside the pool and around the pool area. Zoom in and out of shots to diversify the shoot.
Keep the camera still for underwater shots. Practice holding the camera still and shooting scenes using the camera housing before filming so that everything goes smoothly during the actual filming.
Make use of the camera handle to stabilize shots since you cannot use a tripod while filming underwater. Instead create a tripod posture while filming in the pool by using one hand to hold the handle and the other hand to cradle the housing from underneath.