As you create as much of a ‘low tide’ as you can by using as many pails / containers / buckets as you can to siphon your water out into, don’t overlook the fact that your rockwork might start to work to your advantage. Many passageways will become dead-ends; others can start to be block by nets, sheets of plastic or pieces of glass—anything you can use as dividers to cut off escape routes for your fish. I have used gallon jugs (weighted with water) to cut off escape routes for the fish. My point is, what seems like a virtual impossibility (netting fish with rocks in the tank) when the water is high, can become vastly easier with only 3, 6, even 8 inches of water left.