Pond Boss Forums GENERAL QUESTIONS Water chemistry Thoughts on my water lab results?

I purchased a lab water analysis from a company that also sells pond products. I sent a water sample packed in ice packs via FedEx 2-day. Results and recommendations were returned in 4 days. My main reason for testing was to get a baseline on phosphorous, since I am concerned about a big FA outbreak over the summer.

https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=569653

Here is the gist of the lab results:



Short Term Treatment Options
MetaFloc: is a special bacterial blend used as a phosphate binder and clarity-enhancer.

RapidBac: beneficial bacterial blend used for rapid ammonia removal.

The rest of the report was about a long-term maintenance plan of muck remover, phosphorous remover, beneficial bacteria, pond dye (which I use), aeration (which I have) and herbicides (which I use).

I will follow up with the company with some questions (like, why total hardness and not total alkalinity or KH?). So, I wanted to poll the forum for some additional comments. Do the elevated values of phosphate and ammonia warrant some action in your experience?

When I get water tested, here is what we test for:

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.

Good info esshup, I've been wondering about SS.and have not found much information.

I just sent in a sample to TAMU last week.

You need the numbers for SRP, TK, TKN. The SS you can do yourself with a secchi disc.

Thanks, Esshup, I have one and have measured. Last measurement was 18 inches. It decreased about 6 inches after I began feeding 2X per day. CC and YBH really stir up the water.

Pond is down about 3.5 feet so that does not help matters.

Like several others, we need some serious rain. No significant rain chances anywhere in sight.

Explains a TAMU report.


https://extension.rwfm.tamu.edu/wp-...-water-quality-reports-for-your-pond.pdf

I wonder why they don't address Phosphorus and Nitrogen in ponds? If they don't test for 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 and TKN = Total Kjeldahl Nitrogen 2-6 mg/l then you should find a lab that can because those numbers tell you what you need to watch for in regards to nutrient loading in the pond.

According to 2 labs I called, the following terms are equivalent:

Soluble Reactive Phosphorous (SRP) = Orthophosphates = Free Reactive Phosphates.

My lab test reported Orthophosphate, so I think I got what I wanted in that category.

Inorganic phosphate in natural waters was usually orthophosphate in its original form.

However, it is water soluble, so I suspect all of the lab tests are actually measuring the PO4(-3) anion, so it really doesn't matter what it is called. (Can any experts confirm if that is what is actually measured in the lab test?) That common anion is the way phosphorus is available to the algae and other photosynthesizing plants in the pond. (There can also be P2O7(-4) anions, but I believe they are uncommon in most locations.)

The PO4 anion can bind with the suspended clay minerals in the pond.

(The commentary above is pushing my old chemistry knowledge.)

I have no idea if clay "bound" phosphorus can be released back into the water column as the pond chemistry cycles through natural changes. I suspect clay bound phosphorus that remains suspended in the water column MAY be accessible to some autotrophs.

I also have no idea if a big rain event brought turbid water (that had a high content of clay minerals) into the pond if a phosphorus reading a week after that event would be measurably lower than the reading prior to the rain event? I suspect it might if the chemistry of your pond water does allow for electrically charged clay particles to settle out of suspense.

All of my speculation/questions in red need to be addressed by pond experts, because they are well above my pay grade. (My background is more when the phosphorus is still in the soils.)


Phosphorus in Groundwater (USGS)