Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Looking for advice for 10 year old 0.40 acre pond

Hello I've been reading through the archives and am a new subscriber to the Pond Boss magazine and looking for any advice for my specific pond, situation. I basically have issue with FA that re-grows in 3 days after manual removal and underneath the FA is a thin stringy weed and seems to promote the re-growth of the FA. I have attached some pictures (since they tell the story better than I can) and some additional details on my pond size, what I've tried, etc... The previous homeowner used harsh herbicides that I prefer to stay away from (karmex and copper sulfate). We've been in the house since last August and May of 2012 is last time pond was treated by previous homeowner. Primary use of pond is for fishing and swimming (once I can get rid of the mats of FA).

I live in SE Michigan (Shelby Township)the pond is 11-12 years old stocked with LMB, SMB, some NP, BG and CC. I've read up on many different aeration systems too since that seems to be something I should add as currently only have a irrigation pump 1.5 hp pushing 68 GPM. I am currently battling a Filamentous Algae issue that is covering the whole outer rim of my pond and there is a thin weed, think it's naiad, underneath the mat of FA. I've manually removed the FA many times, but within 3 days it's back in full. I've used some products from local company called the Pond Guys, but had minimal effects on controlling the Algae (I've tried Cutrine Plus granular, Algae Defense and have added their natural bateria products - which did clear up the water).

The intended use for our pond is for fishing and swimming. Before doing any more manual FA removal and weed removal, figure first step is to add a bottom aeration system. I calculated my pond size it's 0.37 acres in surface area (190' x 92' roughly). Max depth near the middle is 15', most of the pond is in the 4-5' range. Should I use one diffuser near the middle or do I need 2?

I've attached pictures also and appreciate all feedback. Thanks in advance. Ron

Don't have any advice (except what you already mentioned, aeration), but someone will be along soon to help. Did I read correctly that you have northern pike in this small pond? With all of those predators in that small of a pond, you may have a biomass issue, depending on how many of each you have.

I only have 10 NP that I added last fall (October) from Imlay City Fish Farm and they were 12-15" at the time. There are way too many larger size BG that I've been slowly harvesting out to avoid having too many fish. Thanks. Ron

I don't think an aeration system is going to help you with the macrophyte (plants) and algae growth as much as reducing nutrients and not swimming in the pond would. As for controlling the plants and algae, Hydrothol granular would be a good choice for your situation. As long as used according to the label it is safe for fish, and has no restrictions on fishing, swimming or irrigation after application.

The plant you have appears to be a pondweed. Looking at the morphology I believe it's sago pondweed. This is easy to control with endothall (Hydrothol) and usually results in season long control if not longer.

Based on the size of the pond I would suggest a rate of 0.3 ppm spread evenly around the perimeter. The product will come off the granular, equilibrate/disperse and control the plants and algae. For this you'd need around 25 lbs.

Algae is a beast to control and you'll likely have to make follow-up applications to reduce densities.

I think a pond that size would be better with 2 or 3 NP.. They will be hungry in short order be careful swimming

JSlade thanks for the feedback. I looked up the sago pondweed and it does look like that is what I have. I've been manually removing the weed now with pond rake and that seems for now to have stopped the algae bloom from re-occurring also. Prior to removal of that pondweed I would remove just the FA on top of the weed and the FA would be back in full bloom within 3 days. Hope this tip helps others, remove the pondweeds underneath the FA bloom first, at least works for me so far.

Thought I would post and update with what I've done and results.

1. Purchased some Aquathol K and used the liquid form on 1/3 of pond edge 5-6' from shore.
2. manually removed the sago pondweed that seemed to hold nutrients for FA rebloom.

The results are very good. No FA rebloom and the sago pondweed removal much easier I believe due to the root system being weakened by the Aquathol K. I removed approximately 90% of the sago pondweed, left some for the smaller fish to hide in from the predators so they can continue to re-populate.

If the sunlight can get to the pond bottom, the FA will start growing there, get dense enough to trap gasses, and break free, floating to the surface. Keep us advised how it goes over the next 5-7 weeks.

Quick update. I identified the algae is really Chara and FA forming on top of that. Manual removal was best option then applied Cutrine plus granular to prevent the Chara/FA from re-starting.

I do have question on water clarity. I live in S.E. Michigan and looking for resource that would be recommended to test and/or come out to my residence and assist me in options for improving my water clarity. I've used products as recommended by local company called "The Pond Guy" and their packets of beneficial bateria but haven't seen any improvements. Rather than trial and error wanted to have my water evaluated by pros and then get recommended options. Thanks in advance for input.

Some turbidity can be a benefit as it reduces light penetration which reduces amount of new plant growth. The clearer the water the more and deeper ALL plants will grow. Then most resort to a heavy dose of blue dye which then selects for algae that are tolerant of blue dye.

Bacteria are a big waste of money, as you now know, if turbidity is due to suspended silt-clay or phytoplankton that could be suspended in the water column for numerous reasons - causes.

I would research the environmental fate of Karmex. It or some other by-product that could persist in the sediments based on what chemical 'soup' was in the pond during application. You do not know how much has been applied in the past which could have been a lot. I would not let my kids swim in a Karmex pond. Mucous membranes are very permeable to chemical exposure.