It is really too late to seed now. Late summer (around Sept.1) is the best time for seeding in Indiana, but since it's October now it is too close to your first frost date to put seeds down and hope for it to make it through the winter. I would advise you to get rid of the sand and pebble layers if you want to have a healthy lawn. If the sand layer is pretty thin you might be fine, but if it's more than a few inches then you need to remove it. Sand doesn't hold water/nutrients very well, but it is great for drainage. Most golf courses use a 50:50 sand soil mix, which is great for drainage, but they have the ability to water daily and use tons of fertilizer.

Have you tried posting this on the container gardening forum? I'd say that selecting appropriate pots or cotainers is the least of your worries, as your winter cold will put pretty much everything at risk. FWIW, plants suited to long term container growth should be selected based on hardiness of at least one full zone (preferrably 2) colder than your regular climate, as that is the effect they will have to endure in a containered situation. That limites your choices to plants with a hardiness of zone 4 temperatures, better with zone 3. Size will have a significant bearing as well - the larger the container, the less likely the soil in it will freeze solid in winter. As for containers, wood will withstand winter cold better than any ceramic pot, but there is a large selection of frostpruf glazed pots originating in Asia that are totally winterproof, at least in my climate. Concrete aggregate should winterize well also but is heavy and very expensive and typically only available to the trade, as they are primarily used in commercial settings. Avoid terra cotta and plastic as neither will withstand freezes for long (terra cotta spalls and plastic cracks). A good quality potting soil - never regular garden soil - should be used, as garden soil is too heavy and doesn't have sufficient drainage. For long term container growth of trees and shrubs, I use a potting soil recommended specifically for them, as their needs are different than those of annuals or perennials or other, faster to mature plants. Adding some coarse, barky compost to regular potting soil will work if your choices of specific potting soils is limited. And always include some slow release fertilizer at time of planting. You will needs to supplement this as time goes by, as the watering requirements for plants in containers will leach any nutrients rapidly out of the soil and they will need to be replaced.

I don't know if this will help but....we have a fish pond/dog pond..no fish the frogs moved in. i noticed the tadpoles were stuck. I put a log across the top. as they got older they hung on the log. Later the frogs used the logs to go back and forth to the water. AS long as the water doesn't freeze to thick. you can wiggle the log to keep an air opening. With a pool you may have to use a large branch. Good luck, but remember we can unfortunately only cheat nature so much.

MrsHanson, we have an above ground pool which we put inground in 2005. It is not one of the brands which are designed for inground, however, we decided to take the risk and see what happened. Since installation, we have invested a 10 foot aggregate surround around the pool. We know that when the liner goes, so goes the entire pool because it will collapse. We had a leak in the liner two years ago, and a great deal of water was leaked, but fortunately, my husband was able to find the leak and patch it. Ours sticks out above the ground about one foot. Keeping our fingers crossed for this year! But, we feel seven years has given us great return on the investment. I will be happy to post a picture of it if you would like, we just took the cover off for summer and it appears a little green, but when clear, it's a beautiful crystal clear blue pool! I will look up the brand as well if you are interested. It's 33x18, and was very inexpensive. Hope this helps! and good luck