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SLAM (Shock Level And Maintain)

A complete algae-removal workflow for residential pools using repeated testing, brushing, and filtration instead of one-time “shock.”

Hub: Troubleshooting · When to use: You have algae, persistent cloudiness with abnormal chlorine demand, or a failed OCLT.
Multi-day commitment
#algae#sanitation#crisis#troubleshooting
Using default values (CYA: 30 ppm, FC: 0 ppm)

Log your actual chemistry to get a personalized SLAM target and track your progress throughout the process.

Log your chemistry

SLAM: Shock Level And Maintain

A residential algae-remediation workflow that uses repeated testing, brushing, and filtration instead of one-time 'shock' folklore.

Residential workflow, not universal code

Poolometer treats SLAM as a residential remediation model layered on top of accurate testing. It is not a public-pool code requirement and it should not replace local health rules, manufacturer limits, or chemistry testing.

  • • Use a current, accurate CYA reading before trusting any SLAM target.
  • • Use FAS-DPD chlorine testing. Test strips are not strong enough for this job.

Personalized target

With CYA at 30 ppm and current FC at 0 ppm, this residential workflow points to about 12 ppm FC.

1

Confirm that SLAM is actually the right tool

SLAM is for algae or persistent organic contamination, not every cloudy-water event.

Use SLAM for visible algae, repeated overnight loss, or contamination that does not clear with routine correction.
Do not default to SLAM for mild cloudiness caused by filtration, pollen, or one bad test result.
Retest FC, CC, CYA, and pH before committing to a multi-day remediation workflow.
2

Prepare the pool and your test workflow

Good data and good circulation matter more than dumping product fast.

Remove debris, empty baskets, and make sure the pump and filter can run reliably.
Verify current CYA and use a FAS-DPD chlorine test.
Lower pH into a normal pre-SLAM range before high chlorine makes pH interpretation unreliable.
Use liquid chlorine only unless a specific product choice is intentional and fully understood.
3

Raise FC to the residential SLAM target

Raise FC from 0 ppm toward about 12 ppm, then verify with a retest after circulation.

Dose with the pump running and allow the pool to mix fully before retesting.
Brush surfaces so chlorine can reach biofilm and settled algae.
Do not guess from strip colors or rely on a one-time 'shock' bag as proof of completion.
4

Maintain, brush, and filter

The 'maintain' part is what makes SLAM work.

Retest FC repeatedly and restore the target whenever it drops materially below it.
Brush daily and keep filtration running long enough to clear suspended debris.
Clean or backwash the filter based on pressure trend, flow change, and the filter manual.
5

Use strict exit criteria

Do not stop because the pool merely looks better.

Water should be clear enough that you trust what you are seeing.
Combined chlorine should be low and stable on repeat testing.
Overnight chlorine loss should pass before you return to normal operation.
6

Return to normal operation carefully

After SLAM, transition back to your ordinary operating target rather than swinging chemistry again.

Let FC drift back to the normal operating range for the current CYA.
Retest pH only after chlorine is back in a range where the pH test is trustworthy again.
Record what likely caused the outbreak so the next fix is prevention, not another rescue.

Common Questions

When should I not start SLAM?

Do not start with unknown CYA, obviously broken circulation, or a problem that is clearly mechanical rather than biological.

Why is the target tied to CYA?

Poolometer uses the common residential FC/CYA model for algae remediation. Higher stabilizer generally means you need a higher FC target to get the same practical effect.

Checklist

  1. 1Confirm it is really an algae problem before you commit to SLAM.
  2. 2Use your CYA to calculate a residential SLAM target and maintain it consistently.
  3. 3Brush, filter, and retest frequently until water is clear, CC is low, and OCLT passes.
  4. 4Know when not to SLAM, especially for stains, metals, or non-organic discoloration.

Related Playbooks

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Recover sparkle after storms, heavy use, or mild organics by separating filtration issues from chemistry issues.

Draining and Refill Planning

Plan staged water replacement for CYA, CH, salt, metals, or contamination without turning a chemistry correction into a structural mistake.