To take the variables out we just send the water sample out to be tested.
If that is what "pond pros" do, then it is almost certainly good advice for amateurs.
What are the components you most commonly get analyzed? What is the ball park cost for that level of testing?
If an amateur does have a pond that is going to require a lot of testing, then I think it would be an excellent idea to confirm that your personal tests closely match with the lab results.
There is an old engineering saying that applies. "The only thing worse than no data, is bad data!"
A "standard" test that we do is typically required because the pond owner is fighting excess nutrients and possibly a cyanobacteria bloom has triggered the call to us. The testing that we have done (and the rest result range that we are looking for) is as follows:
NH3 = Ammonia 0-2mg/l
CL = chloride 10:1 CL to NO2
SO4 = Sulfate 0-1,000 (500 if watering cattle)
NO2 = Nitrite 0-1
NO3 = Nitrate 0.005 - 0.5 mg/l (but can be up to 90 mg/l without harming the fish for a short length of time). Ideal is <0.10mg/L
SiO2 = Silica 5-25 mg/l
SRP = Soluble Reactive Phosphorous this is what feeds plants and algae should not exceed 0.020 mg/L
TP = Total Phosphorous 0.01 - 0.075 mg/l
TKN = Total Kjeldahl Nitrogen 2-6 mg/l
COND = Conductivity 100-2,000
SS = Suspended Solids There is no widely acceptable max reading, but you want a secchi disc reading to be in the 12”-36” range.
For Alkalinity and pH we just use cheap test strips that are commonly used for testing aquarium water or swimming pools. Since the exact number isn't critical and we just need a ballpark, those are good enough for what we need. When talking to the testing lab, make sure that they can test amounts low enough to make a difference (see ranges of results needed listed above). We send out a sample to be tested for nutrients and the test results came back as TP <1.0 mg/l, TKN <10 mg/l which didn't help us at all. That company's test needed a chain of custody letter, the sample packed in a cooler with cold packs, and shipped overnight. For the roughly $300 test cost of packaging and shipping it gave us 0 usable data for what we needed the data for. (baseline for reduction of nutrients)
For pH, we need a result NOW, when it's tested as we don't want the sample to change during shipment. We charge $150 to get those test results, and that is collecting and shipping the sample if we are at a customers pond for another reason. We can have tests run for 23 other metals, that runs another $100.
