Barry,
Welcome to PB! You will find a wealth of information here and you will soon be addicted.
It is good to consider an aeration system prior to any aquatic weed treatments. This will limit your liability of loosing fish due to oxygen depleation as the plants die off.
Your specific question was about self-weighted tubing. There are generally three types of tubing, self-weighted (as you have mentioned), Lead Keeled, and finally no-weighted or black poly pipe.
If you split those up into two categories,
1. Weighted
2. Non-Weighted,
The non weighted is cheaper initally but requires a brick every 3-5 feet to be tied on it or some have used rebar. This type of tubing has a very thin wall which lends itself to several problems. One of the biggest is the fact that this tubing kinks easily. When this happens you have to cut the kink out and add a spice with an insert fitting and hose clamps.
This tubing is also subjected to fish-hook damage. If you hook into it and puncture it, another leak. If you bring it up with all of the bricks, another kink. I think you get the picture.
Lastly the brick tend to shift over time and the tubing begins to float to the surface. Not fun if you plan on swimming.
The alternative is a self-weighted tubing.
Lead keeled tubing is basically the black poly pipe described above with a lead keel attached to make it sink. You get all of the above problems along with the fact that you are introducing lead into your pond!
Lastly the new tubing available is the High Density PVC Tubing. It is available in many sizes, 1/4" up to 1". It does not kink, it is fishhook resistant since it has a 1/4" wall thickness. It is not harmed by extreme weather conditions. This tubing will use common PVC fittings and glue, no hose clamps needed.
This tubing is less expensive than lead keeled or other PVC tubing on the market and it will save you time during installation opposed to the black poly pipe and bricks.
Purchasing a complete kit for your pond and installing it will require only 30-45 min.
Names of the tubings are AnchorLine, Foreversink, Heavy-Set, BottomLine are just a few.
I hope I have cleared up that question for you. Again welcome and we look forward to helping you with your pond.
