We often get asked if you need a lab test to check the health of your dam or lake water. We almost always say no. There are three main reasons.
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The downsides of lab tests
1. A one-off lab test will tell you very little about your water
If you send a water sample to a lab, the first thing the lab will ask is what you are testing for. For instance, if you were testing for water health in drinking water that would entail a whole suite of different tests than if you were testing water health for irrigation water. If you are worried about a chemical spill in the water that would be different again. And these parameters might be 40 or 50 items long–things like carbon, nitrogen, phosphorus, magnesium, sulphide, hydrogen sulphide, nitrogen, ammonium, nitrates, nitrites etc.
It means you need to know exactly what you are looking for to get any value out of a lab test, and if you know this, you probably already know what the problem is.
Added to this, water is always changing in terms of what is in it. In fact, water is the most soluble liquid known to man; being able to dissolve a wider range of substances than any other liquid. This is why water is sometimes referred to as a ‘universal solvent’, because virtually everything that touches water–dirt, rock, organic material, chemicals etc–interacts with it and becomes a part of it to some degree.
So just because you have lab test results, it doesn’t mean you know the health of your water. You simply know the content and quality of water at that one moment. That could change literally days later. For instance, you may have flash flooding that brings in a lot of dissolved material, then over time this excessive nutrient begins to leave the system. You may have times when the aerobic bacteria populations are strong, keeping the aquatic ecosystem in balance and healthy. Other times there may be little to no life. And other times anaerobic bacteria might be the dominant player, releasing foul, toxic odours.
2. You need many lab tests over a long period of time to look for trends (and that’s expensive)
So, you test once. What happens when the water temperature radically changes (extreme heat or cold), you get a lot of rain, a lot of new organic content enters the water etc? You don’t know… unless you test again. The same is true after doing a water treatment. The only way you can know if things have changed on a nano level is by testing again.
This leads to a cycle of endless testing because conditions are always changing. And because of the above, it starts getting very expensive. One water test might cost you $300. After several tests, you are in the thousands and really what have you achieved? Probably not far off where you would be if you simply looked at your water and made some conclusions on your own. Further down we explain what to look for on your own.
3. Lab testing takes a long time
The last thing to consider is that testing water in a lab can take weeks. You have to collect water and send it in, then wait for the lab to test it, then wait for the results. It means by the time you get the results; your water has likely changed in composition anyway. Worse, if you have an emergency, e.g. testing for toxic blue-green algae or ammonia, then you are sitting on a health hazard for this entire time. In most cases this isn’t feasible, you want to get to work treating the water immediately. Especially when you consider that 90% of dam water health problems can be fixed with the same solution–aeration and probiotics. We explain more below.
How to test your water on your own
What is the purpose of your dam?
Firstly, what is the purpose of your dam? Water used for irrigation is a lot different than water used for swimming. Wastewater is obviously different again.
A bit of algae in an irrigation dam isn’t much of a problem, but it’s not good in a swimming dam. Same with water that is a little smelly—often caused by high levels of anaerobic bacteria releasing hydrogen sulphides and methane—it’s not too bad in irrigation but again is a hazard for swimmers. Water that is very smelly, often caused by ammonia, is not good for irrigation or swimmers. Same with blue-green algae, which isn’t algae but rather a cyanobacteria (looks like a green/red/brown oil slick on the surface). This isn’t good for irrigation or swimming because it is extremely toxic.
What is the problem you are trying to solve?
Here are some examples.
- Aquatic weeds
- Algae
- Blue-green algae (bacteria)
- Sludge
- Cloudiness from organic content
- Foul smells
- High levels of nitrogen or phosphorus
The good news is you can solve all the above issues using aeration and probiotics. So, if you have one of the above problems, you may as well forget the test and start treatment.
Struggling to identify the problem? Photograph your dam at different times.
Visit your dam often and take photos of it. How does it appear different at different times of the day and year (different seasons) and after extreme events, e.g. lots of rain, extreme temperatures. This can help you keep tabs on when the problems (e.g. aquatic weed, algae, foul smells), are occurring. This will give you a good idea when to treat your water more aggressively and when you can sit back and let mother nature do her work.
For instance, summer is the time when pests like algae and aquatic weeds are thriving while in winter these pests are growing a lot slower or dormant. So, in summer aeration and probiotics are often very necessary but in winter you can back off the volume. This might mean having your aerator on a timer in winter, so it only goes on for a few hours a day.
Measure macroinvertebrate populations: A better way to measure water health
Scotty Tucker (Founder and Managing Director, Water Quality Solutions) says, “I’ve done volunteer work for the Australian government where you use populations of macroinvertebrates as a way of determining water health. Identifying the number and types of water bugs in a water body can help you determine how good the water quality is. A large population of a diverse range of water bugs is healthier than a dam with a load of leeches and not much else. This method often gives you a more useful indication of general water health than a lab test.”
If you want to boost biodiversity, the good news is it’s the same solution: aeration and probiotics.
Understand 90% of water problems are fixed the same way
Why do you need a lab test to give you great detail on a problem when the solution is the same 90% of the time? This is perhaps the most important point: knowing that most water quality problems are fixed the same way; using aeration and probiotics. For instance, aeration and probiotics (e.g. Biostim) will help solve all the below issues:
- Aquatic weeds
- Algae
- Blue-green algae (bacteria)
- Sludge
- Cloudiness from organic content
- Foul smells
- High levels of nitrogen
It means you don’t need a lab test to help treat any of these issues, you simply need to start treatment. To learn more about how aeration and probiotics work to solve the above issues, click on the links below.
How does aeration improve water quality
How do probiotics improve water quality
It’s worth noting, aeration and probiotics won’t directly kill algae or weed so if you have a major infestation of algae or aquatic weeds and can’t wait for the aeration and bacteria to slowly starve it out, then you may need to look at an algaecide or herbicide. Keep in mind, these chemicals will upset your aquatic ecosystem, including the “good” bacteria who compete with algae and weeds. So, our recommendation if you do use algaecide or herbicide is to use a product like Biostim Accelerator to replenish the “good” aerobic bacteria. Otherwise, the algae/weed will be back, and sooner than ever because you have less allies to defend your ecosystem.
The exception: when to use a lab test
A lab test is usually only valuable for compliance (i.e. you are treating wastewater and have a compliance obligation to keep something like ammonia levels down below a specific level) or when you have a significant chemical spill. You may also have been contacted by a regulatory body who has requested testing to ensure you are meeting standards and need proof of this. Beyond this, you probably won’t get much value out of a lab test.
DIY testing for toxic blue-green algae (at home, no lab)
This biggest issue a dam owner should be aware of is blue-green algae. As mentioned above, this is not actually algae but cyanobacteria, and the bacteria is toxic to people and animals. It’s lethal in humans and animals in high doses. You definitely don’t want animals drinking it or people swimming in it, and you also don’t want to be blasting it through irrigation pipes and making it airborne when watering plants.
If you want to test for blue-green algae, we recommend you use our DIY blue-green algae test. This is a test you can use in the field, no expertise needed, and you get instant results. As well as being faster and cheaper than a lab test, these tests have the benefit of measuring toxins produced by the blue-green algae rather than detecting the presence of blue-green algae itself. This is especially important because even after blue-green algae has been removed from water, it doesn’t mean the toxins have. So, you can use this test after treatment to see exactly when the toxins have gone.
Note: treating blue-green algae with chemical algaecide can actually cause the blue-green algae to stress and dump all of its toxins at once. A safer way to treat blue-green algae is to kill it off slowly and naturally (using aeration and probiotics) so it doesn’t freak out and start releasing more toxins.
Need advice?
We offer free, no-obligation advice on water quality in ponds, dams, lakes and lagoons. Simply fill in this form and we’ll get back to you with treatment options.