I have a little bit of experience with bermuda seed here in East Texas and acidic, clay soils. The seed comes in two forms, hulled and un-hulled. If you have good conditions, the the hulled is the way to go. The seed is like a walnut,but smaller. The hulled has the shell removed so you are just buying the seed. Soil temps should be around 80 degrees and of course, you will want water. I've found that very little of it washes away when it rains, but it does sort of start off patchy.
If conditions are not perfect, the the un-hulled is the way to go. The seed will sit there until conditions are right and the hull rots off. This is what I've done when planting late in the year, or early in the year.
When buying seed, be sure to know how much seed you are buying. All of the big stores sell bermuda seed, but most are between 25 to 50% seed, with the rest of the bad being filler material. I've shoped around and found farm supply store that sell pure seed by the pound. I can buy one pound or one hundred pounds from them. They just weigh it out for me. This has been proven to be the very best price per pound of pure bermuda seed that I've found.
As for your rye grass, I'd cut it down and wait about a week, then spread the bermuda seed. Once you spread the seed, you can't cut again until the bermuda is established. When young, it will look just like the rye grass. It will take a month or so for it to go from single blades to sending out runners. Once you get those clumps of bermuda with runners spreading out, you are set. Then it's just a matter of time for it to take over everything. Ignore the rye grass, it will be dead in a few months anyway.
When spreading the bermuda, I mix two parts dry sand with one part seed in my broadcast spreader. The sand helps thin out the amount of seed you spread, but is also very helpful in letting you know where you've been. When doing an acre or more, it's real easy to forget exactly where you've already spread the seed, even when looking at your tractors tire tracks!!! The sand shows up good and tells you for sure if you've done an area or not.
On the topic of sealing your screws and possible leaks, use roofing sealant. It will cost a little more then silicone, but is allot better. There are several to choose from, but my favorite is the Henry brand sold at Home Depot. I've had good luck with other brands too, but Henry is really some good stuff. It will stick to the pipe and seal it like nothing else. It will also stick to your fingers and provide some good fun in getting it off of you!! hahaha
Great pictures. That's really impressive to see the water coming out of that 12 inch pipe. One thing that you mentioned is the vigration of the pipes. While PVC has considerable flex to it, failure does occure from movement. Larger pipe is more prone to this then smaller pipe. It's why most larger water pipes, 2 inch and bigger, are gasketed. This allows them to slide in and out of each other and retain their seal without breaking.
On your system, I would put concrete around the end of that pipe and set it on a footing to lock it into place. I can buy a one yard buggy of premixed concrete from United Rentals and pull it with my truck. That's what I'd use and about how much concrete I think it will take to really lock it into position. Dig a hole, build the forms and add a little rebar. If you buy sacks, be sure to mix them first. Don't do the fence post routing and dump them into the hole and add water to the top. While this works for fence posts, the strength of the concrete done that way is half of what it is if properly mixed concrete. Properly mixed means as dry as possible. The more water you add, the weaker the mix will be.
Good luck, pond looks amazing.
Eddie
