ToolboxLab TestingNitrogen Sequence Surface Water Test

Labeled water sample bottles packed for certified lab analysis

Lab Testing

Nitrogen Sequence Surface Water Test

Name: Nitrogen Sequence Surface Water Test
Brand: Lake Pulse
Price: 225.00 USD
Availability: InStock

Three forms of nitrogen — the panel that shows where nitrogen is coming from and what it is doing.

$225

Checkout arrives with the store connection. Orders attach to the lake on your account.

Overview

Nitrogen doesn't exist in a lake as one thing. It cycles through several chemical forms, and which form dominates tells you where it came from and how available it is to algae. This panel measures the three that matter most: nitrate, ammonia, and total Kjeldahl nitrogen. Read together they are a sequence, not three separate numbers — hence the name. Methods EPA 300.0 for nitrate, EPA 350.1 for ammonia, and EPA 351.2 for TKN, all reported in milligrams per liter (mg/L).

What's measured & how

3 parameters · Nitrogen species panel

What's measured & how for Nitrogen Sequence Surface Water Test
Parameter	Result type	Unit	MDL	RL	Analytical method
Nitrate as N	Quantitative	mg/L as N	0.01	0.1	EPA 300.0
Ammonia	Quantitative	mg/L as N	0.04	0.05	EPA 350.1
Total Kjeldahl Nitrogen (TKN)	Quantitative	mg/L as N	0.249	0.5	EPA 351.2

Nitrate as N
Result type:
Quantitative
Unit:
mg/L as N
MDL:
0.01
RL:
0.1
Analytical method:
EPA 300.0
Ammonia
Result type:
Quantitative
Unit:
mg/L as N
MDL:
0.04
RL:
0.05
Analytical method:
EPA 350.1
Total Kjeldahl Nitrogen (TKN)
Result type:
Quantitative
Unit:
mg/L as N
MDL:
0.249
RL:
0.5
Analytical method:
EPA 351.2

MDL = method detection limit. RL = reporting limit. Provided by the performing laboratory.

You get

Signed laboratory report, filed in your lake's Documents & Reports
Each result loaded into your lake's Data Library (Plus, Lake Admin, PRO)

How it's produced

Test type: Nitrogen species panel
Sample: One surface-water grab sample, collected by you with the kit
Return shipping: Prepaid 2-day return to the laboratory
Analyzed by: Independent accredited partner laboratory, with full chain of custody
Method basis: EPA-approved
Turnaround: 5 business days from lab receipt
Analytical method: EPA 300.0; EPA 350.1; EPA 351.2

Product category

Physical ProductShips to you
ConsumableLab testing

Availability
Kit ships in 2 business days
Shipping
Flat-rate to your front door. Shipping details
SKU
SL-SL-SW-E-S-UJ2

Example result

0.12 mg/L as N

Method: EPA 350.1

Elevated ammonia points inward — internal cycling or fresh organic input

Turnaround

Results are available within 5 business days of the lab receiving your sample.

What problem does this solve for our lake?

Total nitrogen alone is a blunt instrument. The forms are what carry the information.
Nitrate (EPA 300.0; MDL 0.01 mg/L, RL 0.1 mg/L) is the fully oxidized, highly mobile form. It travels easily through soil and groundwater, which makes it the signature of external inputs — lawn and agricultural fertilizer, and septic leachate that has had time and oxygen to convert. Elevated nitrate points outward, to the watershed.
Ammonia (EPA 350.1; MDL 0.04 mg/L, RL 0.05 mg/L) is the reduced form, and it means something quite different. It indicates either fresh organic input — recent sewage, manure, decaying material — or low-oxygen conditions in the lake itself, where ammonia is released from bottom sediments during summer stratification. Elevated ammonia often points inward, to the lake's own internal cycling. It is also directly toxic to fish at elevated levels, particularly when pH and temperature are high.
Total Kjeldahl Nitrogen (EPA 351.2; MDL 0.249 mg/L, RL 0.5 mg/L) captures organic nitrogen plus ammonia — nitrogen bound up in living algae, bacteria, and decaying material. A high TKN with low nitrate typically means the nitrogen has already been taken up and converted into biomass.
The pattern across the three is the diagnosis. High nitrate with low ammonia and low TKN suggests active watershed loading into a lake that hasn't yet used it. Low nitrate with high TKN suggests the lake has consumed available nitrogen and turned it into algae. High ammonia suggests either a fresh contamination source or an oxygen problem at depth.

What's included?

A complete nitrate, ammonia, and TKN test kit shipped directly to you
All materials required for clean, contamination-free sample collection
Step-by-step collection and preservation instructions
Prepaid 2-day return shipping to our accredited partner laboratory
Analysis by EPA-approved methods at an accredited partner laboratory, with full chain of custody
Results loaded automatically into your lake's account

What's not included

Sample collection. You collect the sample; we supply everything you need to do it correctly.
Boat, dock, or shoreline access to your sampling site
Depth-profile sampling. This is a single grab sample unless you order multiple kits.
Ice or a cooler for shipping, which you supply
Treatment, remediation, or applicator services
A written management plan. The Boathouse can help you interpret results and decide next steps.
Phosphorus. If you want the full nutrient picture, order the Nutrient Profile Surface Water Test or add a Total Phosphorus Test.
Nitrite, measured separately
Depth-stratified sampling, which is what you need if you suspect ammonia release from bottom sediments

Requirements

A sample collected from open water at a consistent depth
Same-day shipment after collection, kept cold — ammonia in particular is unstable and will change if the sample warms or sits
A Plus, Lake Admin, or PRO subscription to have results loaded into your Lake Pulse account
Questions about site selection, timing, or which test fits your lake? Contact the Lake Pulse Boathouse before you order.

What you get back

Results

Nitrate, ammonia, and TKN each reported in mg/L with detection and reporting limits
Total nitrogen by summation, for trophic classification and for the nitrogen-to-phosphorus ratio
A source signal: whether nitrogen is arriving from the watershed or cycling from within the lake
Results load automatically into your lake's Data Library in the Lake Pulse Portal
Data can be charted in the Analytics Hub, used to trigger alerts, or shared with your board and members
A downloadable, signed lab report is filed in your lake's Documents & Reports for permanent reference
Results are found in your lake's portal, accessible only to Plus, Lake Admin, and PRO subscription tiers

Pro tips

This is the diagnostic panel, not the screening panel. If you have already found elevated nitrogen and want to know where it is coming from, this is the right test. If you are starting from nothing, start with the Basic Lake Test.
Ammonia is the one to watch after a fish kill. Elevated ammonia alongside low oxygen is a common signature.
Add phosphorus, always. Nitrogen results without phosphorus cannot tell you which nutrient is limiting, and the limiting nutrient is the one worth managing.
Sample after rain to catch watershed nitrate; sample in late summer stratification to catch internal ammonia. The timing you choose determines which source you will see.
Ship it cold and ship it today. Ammonia degrades faster than almost anything else on the menu.

Results sync to the Portal for Plus, Lake Admin, and PRO subscribers

Results from this product land in your lake's shared record in the Portal — next to everything else your lake has ever measured, instead of in an inbox.

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About these results

Every result shows the date and time the sample was collected. Results reflect one sample, collected at a specific place and depth, and analyzed by an independent accredited laboratory using the method listed on this page. Lake conditions change across a lake and over time, sometimes within hours, in ways a single sample may not capture. Every method has detection and reporting limits; where the laboratory provides them, they are reported with your results. A detection is not a diagnosis, and a non-detection does not prove absence. Results are not a regulatory or compliance determination unless the agency involved accepts them as one. Results can help you make decisions about safe swimming and water use, but no result is definitive for every place and time. It is always good practice to check posted signs and your state or local health authorities. Recommendations are options to consider; decisions, and responsibility for any action taken, rest with you.

Questions on this?

Our team can help you choose the right solution for your lake, explain how results sync to your Portal, or point you to the right subscription.

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