Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Pond Dye or floating shade

Saw an ad for used Billboard Vinyl that got me thinking one of these might block the sun much like pond dye.

Not sure if I would attempt to float it with PVC pipes or some other scheme or just say fuggedaboutit and go with pond dye.

There was a thread going a few years back about shading a pond with opaque material to block some of the heat gain in a southern pond. Our member anthropic participated. My interest at the time was to increase the heat gain in my cool water pond to increase productivity.

I don't recall whether we came to any conclusions about suspending material as you are suggesting. I tend to think that blocking the sunlight would limit beneficial algal production (plankton) in addition to blocking macrophytic growth.

It's possible your idea has not been tested. If you decide to give it a try, keep this thread up to date please. We'd all learn something valuable.

I think both would reduce macrophyte and phytoplankton growth. Essentially one is enforcing a limitations. There are other possible limitations you could force. For example, ph. Or sequestration, (Alum). It may be if you knew the extant that Alum would reduce your ph without adversely affecting the fish you could use a reduced amount of it and save on lime. Usually, however, people use it in combination with lime.

Given the choice of pond dye or floating vinyl ... I think I would opt for the dye. Disrupting atmospheric interaction with the pond surface might not be conducive to the best water quality.

Soils can have a substantial amount of organics (can exceed 1 ton/acre dry weight). Usually only a fraction of this gets recycled annually feeding growth of phytoplankton and macrophytes. As odd as this sounds, it may be better to have the vinyl on bottom to restrict recycling of existing soil nutrient. This may be enough to prevent rooted macrophytes that do not have the ability to pierce the vinyl (some probably do). It probably wouldn't help as much as dye for something like FA.

What are your goals? Dyes like Aquashade block blue/yellow sunlight, and can help block deeper aquatic plants, but do little to control shoreline plants and algae. Dyes applied at the manufacturer's recommended rate, can also disrupt the bottom of the food chain, which you don't want.

"IF" I was going to try to block sunlight in my pond, I'd start out by trying something affordable and manageable like pink insulation board, and get comfortable with the logistics needed. 8 sheets could cover a 16'X16' area for less than $100, so if it doesn't work, you haven't broke the bank. If it does work like you want, then you could always get more water resistant rigid panels if needed. Billboard vinyl would be great, but I would think it needs some type of grid flotation to keep it from sagging, and I wouldn't know how to do that in a manageable manner.

I just thought of this and it may not apply but it may be worth considering. It could be that shading with something that blocks sunlight by floating on the surface may possibly work the opposite as anticipated. The nutrients under the blocker could find their way into the rest of the pond stimulating more excessive growth there. So definitely not the same situation as laying a board on grass but if one does this the nutrients (& water) under the board are available to grass growing around the edge and this stimulates growth around the edges. With dye the shading is throughout the pond so it effectively limits the energy available for submerged macrophytes and phytoplankton everywhere.

To FireisHot's point of applying dye at recommended rates interrupting the bottom of the food chain, I have witnessed dye destroy the best trophy BG water I have up to now fished in Texas (I've not had the privilege of fishing Al's big BG). The pond was undergoing annual increases in FA production until community members complained of a midsummer FA float that forced action. That was 3 years ago and the dye continues and the fishing now sucks. So maybe there is some more reasonable treatment than the one the dye company recommends? I don't know. Is there a some formula that one can calculate the shading provided by a given treatment rate (grams dye/1000 cu ft or something like that)?

My goal is to kill off the water shield without using herbicide.

Although it seems like an herbicide is my best bet.

Since water shield can (and does) grow to the surface, no amount of dye will kill it off. Applying the correct herbicide, at the correct rate at the correct time of the year is your best (and safest) bet.