Going Bigger
Your fish are having babies and all your plants are full and beautiful. You go to the nearest pond store and you fall in love with more fish and more plants that you just have to have. Basically, you have grown out of your pond so now it is time to make a decision. You either enlarge the pond you have or add another pond to your landscape.

If you decide to enlarge your pond, there are two ways you can go about this. First, you can splice your pond using seam tape. This a little risky because you have to make sure the seam remains watertight. The other route would be to take out the smaller liner and add a larger liner. Either route you go, you will need to remove all your fish, plants, and rocks before you start digging.
You might also think about putting in a second pond with a stream and waterfall connection. This is a great idea because it adds a natural look to the landscape and gives you a wonderful bubbling sound. For this to work, you have to raise one pond higher or lower than the other so keep that in mind if you try this route.
You might also try building a new pond next to the older pond and using a fake bridge to connect them. This gives the appearance of one large pond plus a place to go for a great view. If you use this method then the ponds will look as one as long as they are constructed on the same level. If you like you can even connect the two using a section of pipe and one or two bulkhead fittings connecting the two ponds. If you use a three-inch pipe and bulkhead some fish can swim back and forth through the bulkheads and one filtration system can be used. If you want to restrict the movement of the fish then you can use a bulkhead screen on the pond side of the bulkhead. This is method is a little tougher to do but can be worth the effort.

So, now you have some ideas and suggestions to work with. Whatever you do, remember that your fish will grow and have babies and your plants will multiply. Make sure your pond or ponds are large enough to accommodate these increases. Also, keep in mind, if you are enlarging or adding on, you may need to increase pump pressure and filtration.