Iluka Descend - 500gm - pH Reducer / Dry Acid
Iluka Descend - 500gm - pH Reducer / Dry Acid is temporarily out of stock and will ship as soon as it's available.
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Don't Guess - Ask Us!
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Delivery and Shipping Info
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Warranty Information
Warranty Information
Iluka Descend - 500gm - pH Reducer / Dry Acid is temporarily out of stock and will ship as soon as it's available.
Iluka Descend - 500gm - pH Reducer / Dry Acid
Iluka Descend lowers the pH and Total Alkalinity of spa and hot tub water. Water high in pH and /or Total Alkalinity can corrode equipment, cause scale formation and metal staining, irritate skin and eyes of bathers and reduce the killing ability of chlorine over algae and bacteria.
- Physically Stocked, unlike most "drop-shipping" websites.
- Shipped from VIC, NSW, WA, QLD
- pH should be maintained in the range of 7.2 – 7.6.
- Total Alkalinity should be maintained between 125ppm-150ppm.
- It is recommended that your spa water is tested prior to adding pH & Alkalinity Reducer/ Alkalinity & pH Increaser.
- DO NOT add more than 25 grams of pH & Alkalinity Reducer per 1000 Litres of water at any one time.
- Always adjust the Total Alkalinity before adjusting the pH.
This range provides everytrhing you need to enjoy a healthy bathing experience, maintain crystal clear water, and minimise chemical usage.
- Iluka Start-up Kits - Bliss, Seachange, Purify, Brilliance, Klenz, Elevate, Descend, Hardup, 3 in 1 test strips, water sample bottle, 60ml Measuring Cup. We also recommend you add a 1kg Iluka Eliminate
- Iluka Bliss - Sea minerals
- Iluka Seachange - Oceanic ingredients
- Iluka Brilliance - Water Polisher
- Iluka Purify - Sanitiser
- Iluka Eliminate - Chlorine-Free Oxidiser
- Iluka Elevate - Total Alkalinity & pH Increaser
- Iluka Descend - pH Reducer
- Iluka Hardup - Calcium Hardness Increaser
- Iluka Klenz - Cartridge & Surface Cleaner
- Iluka Purge - Pipe & Biofilm Remover
- Iluka Sudsaway - Foam Remover
Note: Dry chemicals are sold by weight, not volume. Due to differing densities of various chemicals, some containers may not appear 'full' when they are actually the correct weight.
To the layperson, plumbing sizes and their names can be confusing due to the nominal sizes and naming conventions used.
This is not something we made up. Plumbers and manufacturers have used nominal (meaning ‘by name only’) sizing for decades.
Simply put, in plumbing, named sizes are often not the actual measurements of the pipe, fitting, or part. A PVC pipe called “50mm” or “2"” does not measure 50 mm anywhere. Instead, it follows nominal sizing, an internationally-standardised naming system.
Almost all fittings we use in the pool & spa industry use “pressure PVC” pipe & fittings. Do not confuse with “DWV” or other pipe & fittings and their names and sizes.
Use the Outside Diameter (OD) to check your pipe against fittings. Below is a quick reference for common spa & pool pipe sizes:
| Imperial Name | Metric Name | Pipe Diameter (OD) |
|---|---|---|
| 1/2" | 15mm | ~21.2–21.5 mm |
| 3/4" | 20mm | ~26.6–26.9 mm |
| 1" | 25 mm | ~33.4–33.7 mm |
| 1.5" | 40 mm | ~48.1–48.4 mm |
| 2" | 50 mm | ~60.2–60.8 mm |
| 2.5" | 65 mm | ~75.2–75.5 mm |
To reiterate, these are nominal sizes and are designed to fit matching fittings — not to measure what their name suggests. These are based on PVC Pressure Pipe AS/NZ 1477 Dimensions1.
- º Internal diameters vary slightly by manufacturer and class.
- 1 Not all pool/spa fittings match these dimensions exactly. Some do not follow Australian or international standards. Chinese spas may use proprietary fittings.
Understanding Plumbing Sizes & Nominal Measurements
Plumbing sizes can be confusing. PVC and many other pipe systems use nominal sizes—the size is a name, not the exact measured dimension. This convention is used across most pool and spa systems and other plumbing areas so that pipes and fittings remain compatible.
Why pipe sizes don’t match the measurements
The Nominal Pipe Size (NPS) system standardises pipe dimensions so that pipes, fittings, valves, and accessories interoperate.
Plumbers work with these nominal names every day, but DIYers can be tripped up if they try to match by a tape-measure alone.
How to Measure Pipe Correctly
-
Pipe size is identified by:
- The pipe’s Outside Diameter (OD).
- The fitting’s Inside Diameter (ID) (socket opening).
- Pipe Class / Schedule (e.g., Class 9, 12, 18 or Sch 40) relates to wall thickness and therefore the Internal Diameter (ID) and pressure rating.
- The outside diameter of a fitting is not useful (wall thickness varies by manufacturer).
Hose & Tube Dimensions
Common flexible hose sizes used in pool/spa systems (approximate IDs).
| Imperial Name | Metric Name | Inside Diameter (ID) |
|---|---|---|
| 3/8" | 9–10 mm | ~9 mm |
| 3/4" | 19 mm | ~19 mm |
BSP – British Standard Pipe Thread Sizes
BSP thread names are also nominal. The thread OD will not equal the nominal name.
| BSP Thread Size Naming | Outside Diameter (mm / inch) | TPI |
|---|---|---|
| 1/16" BSP | 7.7 mm / 0.304" | 28 |
| 1/8" BSP | 9.7 mm / 0.383" | 28 |
| 1/4" BSP | 13.16 mm / 0.518" | 19 |
| 3/8" BSP | 16.66 mm / 0.656" | 19 |
| 1/2" BSP / 15 mm | 20.99 mm / 0.825" | 14 |
| 5/8" BSP | 22.99 mm / 0.902" | 14 |
| 3/4" BSP / 20 mm | 26.44 mm / 1.041" | 14 |
| 7/8" BSP | 30.20 mm / 1.189" | 14 |
| 1" BSP / 25 mm | 33.25 mm / 1.309" | 11 |
| 1-1/4" BSP | 41.91 mm / 1.650" | 11 |
| 1-1/2" BSP / 40 mm | 47.80 mm / 1.882" | 11 |
| 2" BSP / 50 mm | 59.61 mm / 2.347" | 11 |
| 2-1/4" BSP | 65.71 mm / 2.587" | 11 |
| 2-1/2" BSP | 75.18 mm / 2.960" | 11 |
| 3" BSP | 87.88 mm / 3.460" | 11 |
| 4" BSP | 113.03 mm / 4.450" | 11 |
| 5" BSP | 138.43 mm / 5.450" | 11 |
| 6" BSP | 163.83 mm / 6.450" | 11 |
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