Pool Alkalinity Increase
Calculator
Results
- Increase needed (ppm)
- 40
- Product to add (g)
- 3,400
- Product to add (kg)
- 3.4
- Water volume (m³)
- 50
Pool and aquarium results
| Increase needed (ppm) | 40 |
| Product to add (g) | 3,400 |
| Product to add (kg) | 3.4 |
| Water volume (m³) | 50 |
formula-map diagram
- Increase needed (ppm)
- 40
- Product to add (g)
- 3,400
- Product to add (kg)
- 3.4
- Water volume (m³)
- 50
Pool and aquarium relationship
Formula
product = (target − current) × label dose × volume(m³)= 40
Note
This is a simplified model: it applies a standard geometric or physical formula to the numbers you entered. Volumes assume a regular shape and an even average depth, and the kidney shape uses the common 0.45 × (A + B) × L area approximation. Chemical doses convert a target change into a product mass using the strength or label dose you enter, because the amount of active ingredient varies from product to product; they ignore pH, temperature, buffering, sunlight, bather load and existing chemical interactions. Heating uses Q = m × c × ΔT with c = 4186 J/kg·K and ignores heat losses to air, ground and evaporation; evaporation and cover figures use the rate you enter, not local weather. Aquarium stocking by surface area is a rule of thumb, not a biological limit. Always follow the product label and test the water before and after dosing, and consult a pool or aquarium professional for anything you are unsure about.
More in Pool and aquarium
See all →Frequently asked questions
What does total alkalinity measure, and why raise it separately from pH?+
Total alkalinity measures the water's capacity to buffer pH changes — mainly carbonate, bicarbonate, and hydroxide ions — and is corrected first because unstable alkalinity causes pH to swing unpredictably even after you fix it. The calculator uses sodium bicarbonate (baking soda) dosing rates to bring alkalinity into the 80-120 ppm target range.
Why does raising alkalinity often raise pH too, and is that a problem?+
Sodium bicarbonate raises both alkalinity and, to a lesser degree, pH, since they're chemically linked through the carbonate buffering system. This is usually welcome if pH is also low, but if pH is already in range, add alkalinity increaser in smaller increments and re-test, since overshooting pH is easier to avoid than to undo.
Why does the calculator recommend adding this in stages rather than all at once for a big correction?+
Large single doses of sodium bicarbonate can cause localized cloudiness and don't dissolve evenly, and big jumps also make it harder to gauge whether you've overshot the target. Adding in increments of roughly 25 ppm at a time, waiting several hours between doses, gives more predictable and accurate results.
What happens if total alkalinity stays too low even after dosing?+
Persistently low alkalinity usually means an offsetting factor is present — very low pH, a leak diluting the pool with fresh source water, or heavy dilution from rain — that is neutralizing the buffer as fast as you add it. Confirm pH and look for a source of continuous water exchange before adding more product.
Can alkalinity be too high, and what does that cause?+
Yes — above roughly 120-150 ppm, water becomes over-buffered, making pH resistant to correction (it tends to drift high and stay there) and can contribute to cloudy water and scale formation, especially combined with high calcium hardness. If alkalinity is too high, it's lowered with muriatic acid in a different process than this calculator's increase dosing.