Pond Boss Forums AQUATIC VEGETATION Balance of plants in the environment How to control coontail in spring fed pond?

Thanks again, Kelly, for the recommendations and the label info. This does trigger a few additional questions.
1) is there a water temp that tells that it's ok to start using the herbicide. Most of the labels say something like in spring or early summer when biomass is reduced and plants are rapidly growing. I will be out of the area for about 6 weeks beginning in mid April. How long after the first half could the remainder be done and still minimize DO issues?
2) I don't have chemical injection equipment. I saw online generally how they are put together. I have a 25 gal sprayer that maybe could be used with some diy hoses with weighted pipes and nozzles. When I read the hardball label I interpret that the entire treatment area (ave depth say 4 ft) must get to the recommended ppm. To get 21 lb 2-4-D would take about 12 gal of hardball per acre. Am I figuring that right? To get the equivalent amount of 2-4-D would take 110 lb of granular navigate?
3)My pond kinda has two "bays". Can I treat each bay totally or is it necessary spread out the partial treatment areas to minimize DO effects. ( are the fish smart enough to move to better oxygenated water if they are threatened with lower oxygen?)
4) How can I reduce clarity? Does dye work for stream fed ponds? Should fertilization be considered once weed problem gets managed? Talked with extension folks who don't understand it. They recommend getting a soil sample of pond bottom. I'll be doing that.
As usual, thanks again, Kelley. I bet you get tired of sharing your info with us uninformed folk. It is very much appreciated for sure.

It's a delicate dance to avoid DO-issues once biomass and water-temps reach critical levels. Killing a large biomass in cooler water is equally as risky as killing a smaller biomass in warm water. The only way to REDUCE the risk of DO problems is to avoid both scenarios.
In my experiences, DO-crashes are "mostly" due to large-scale die-offs of filamentous algae populations; but I've also caused a fish-kill (both predicted and client-authorized) during an aggressive coontail treatment in mid-summer.
For your described situation, I suspect that treating a milfoil population that grows primarily in only a section of the pond - early season - is unlikely to induce a DO problem; but no guarantees.
Sub-surface injection can be accomplished with many home-made setups, and your 25-gal ATV-type sprayer is well suited for such purposes. Replacing the spray-gun with a perforated lead-filled pipe affixed to the end of an extension-hose should suffice.
The label-rate for 2,4-D is somewhat ambiguous and misleading. I've had good results (on milfoil) with far less product than the label prescribes; but it also depends upon several site and treatment-factors. Probably best to discuss this aspect of any potential treatments.
Staggered whole-bay treatments are preferable, and shouldn't pose a DO issue throughout the entire lake. The demise of milfoil; post-treatment, will be gradual enough that DO isn't likely to cause an issue - in most cases.
Lake dyes probably aren't a viable option in ponds that have perpetual water-transition - depending on the rate of transition and your pocketbook. Even then, a lake dye only "works" when there's adequate depth available for sunlight-filtration. Same thing applies to fertilization. And, for that practice to work, other water-quality factors must be suitable for the fertilizer to produce a adequate phytoplankton bloom.
I'll shoot you an email with my ph#. Maybe we can dialog one evening this week concerning site-factors and potential treatment options/methods.