How to Floc a Dam in 24 Hours

We want to talk to you about flocculation and how you can get it done quickly and easily to enjoy clear water overnight.

What is Flocculation?

Flocculation, also called floccing, is where small, suspended particles in the water are clumped together to form larger masses we call “flocs”. The flocs sink to the bottom of the water, leaving the upper layers clear. 

Why Testing Matters

Before you floc your dam, you should always do proper testing. You need to know how much flocculant you should actually use, and you can’t do that without testing. It’s easy to do and you don’t need specialist equipment — just your flocculant, water from your dam, and some jars.

You need to test because when you scale up to do your whole dam, you need the right amount of product. Too much or too little product won’t work — it’s got to be right. And you need to get the dosage right because if you don’t have enough and you figure it out halfway through, you can’t just top it up. You have to start over again using the right dosage.

Here’s how you can do a test:

1. Collect samples from different spots in your dam:
2. Dilute your flocculant
3. Measure and add different doses to your jars: Use a pipette or dropper and add different doses, e.g. 1ml, 2ml, 3ml per litre
4. Stir to mix
5. Observe

If nothing happens, you put in too little; if everything stays loose and doesn’t settle, you put in too much. Keep trying until you get a clear result.

How to Use Flocculant

First, you need to figure out exactly how much flocculant you need for your dam. For this guide, we’ll use the figures for a dam we did recently, where we needed 20 litres of flocculant. We diluted it about 5:1; you can go up to 10:1. 

The dilution is more about making sure you have enough product to distribute over the whole dam. It’s no good diluting it 1:1 if you need 20 litres but run out halfway through spraying. The flocculant has to actually contact the particles in the water, so you need an even spray all over it.

Mixing Helps:  If you’ve got something to mix it around — an aerator, a pump, anything like that — that’s a good idea. You may need to mix it around temporarily, and then once you see floc formation or activity happening, shut off your mixers and let it drop and settle. 

Our test dam was a small dam, so we were able to spray the flocculant from the shore. In a larger dam, you would probably need to spray from a boat. You need to run the sprayer behind the boat motor and let the motor mix it. It’s easy enough to whizz around the dam to get it spread out. Don’t just pour it into the corner and forget about it.

Spray Consistency

You can use different types of spray consistencies. You can use a fine mist spray, which is great for behind a boat motor. It gives great coverage, but it’s on the finer end of what you want to be using.

You can also go with a sprayer that has heavier droplets. That’s good when there’s just a little wind, since the wind can help disperse some of the droplets.

Waiting for Floc Formation

After you’ve been spraying for a while, you’ll notice some different activity happening in the water where the floc is starting to form. You should see little streaks and clumps, and that’s a good sign that the process is working. 

It’s not as simple as just using all of the calculated dose; you don’t want to overdose because the product doesn’t work as well. You’re aiming for a fluffy floc around pinhead to matchhead size. If you reach that point, stop spraying and let it settle.

Flocculant and Aeration

Our test dam is a very shallow dam; it’s only about waist deep, but it’s got a solar aerator in there that we were testing. That’s perfect for floccing: I could turn that on for a little while and help mix some product around. 

If you have an aerator, it’s a good idea to use it for mixing, but you don’t want to turn it on for too long. Especially in a shallow dam like our test dam — it’s so shallow it might actually stir up the bottom and do more harm than good. But we’ll just fire it up for a little bit and give it a go.

If you use an aerator for mixing, you should see different kinds of swirls in the water. However, you don’t want to leave it on for too long.

Results

A few hours later, you can start seeing the water clear up. Hopefully, overnight, the flocculant finishes and the floc drops, and we come back to a clear dam. You’re not going to see crystal clear water like a swimming pool — you’re going to get a more natural look with the mud dropped out.

Consider a Long-Term Approach

Before you floc, think about the reasons why you needed to floc in the first place. If you don’t solve these problems, you’ll get muddy, turbid water again. Think about:

– Bare, eroding banks letting dirt in

– Waves or wind battering exposed shorelines

– Carp, yabbies, or other fish and pests that stir up the mud

– Runoff delivering fresh sediment and material

If you fix the reasons why the dam is muddy in the first place, then you floc, you can enjoy the results for longer.

Want to Learn More?

Do you want to learn more? Or maybe you’re interested in flocculant, aeration, or biological treatments for your water? We can help. Get in touch. We can assess your water, provide FREE expert advice, and supply you with the right products for your situation.