Description

High Performance Filtration Media

Filtration media, 3-5 micron filtration, single layer with expanded surface area, With high opal content for hardness & longevity, this is a high performance filtration media for all water and wastewater applications.

NextSand is a special zeolite based media, exclusively sourced from Western USA, and has been proven in demanding applications replacing standard multi-media and anthracite sand filter systems. Use NextSand to upgrade the performance of  your pressure or gravity filter.

Supplied in 25 litre bags (0.88KGs/Litre), nextSand is easy to integrate into your filtration plant. Note sure how many bags to order? Send your enquiry to hello@waterform.co.nz and we will be glad to assist.

nextSand™ System Design Guide – Metric Edition

All values converted from the original US customary units for ease of design and operation in metric‐based regions.

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1. Overview

nextSand is a high‑purity filtration media with high porosity (~27 m² g⁻¹) that enables higher solids loading and longer run times compared with conventional sand and multimedia beds. The standard design uses a 0.91 m bed depth (36″) with 50 % free‑board.

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2. Service Flow Design

2.1 Recommended Filter‑Bed Flux Rates

Bed Flux (m/h)	Operating mode	Typical application
25 – 29	Conservative	Pre‑RO/NF guard filtration, potable‑water SDI/NTU control
34 – 39	Moderate	General industrial polishing, cooling‑tower make‑up
44	High	Surface/ground water with low NTU/TSS where maximum throughput is needed

2.2 Pressure Vessel Sizing & Service Flow Rates

(Metric equivalent of Table I — flow rates are m³ h⁻¹)

Bed Flux (m/h)	Ø305 mm	Ø457 mm	Ø610 mm	Ø762 mm	Ø914 mm	Ø1219 mm	Ø1829 mm
29	2.0	4.8	8.6	13.4	19.3	34.1	77.2
37	2.7	6.1	10.7	16.8	24.1	42.9	96.5
44	3.2	7.3	12.7	20.2	28.8	51.6	115.6
49	3.6	7.9	14.3	22.3	32.0	57.0	128.3

Bed volume and surface area for 0.91 m media depth

Tank Ø	Bed Volume (m³)	Surface Area (m²)
305 mm	0.07	0.07
457 mm	0.15	0.17
610 mm	0.27	0.29
762 mm	0.42	0.46
914 mm	0.60	0.66
1,219 mm	1.07	1.17
1,829 mm	2.40	2.63

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3. Backwash Design

3.1 Water‑Temperature / Viscosity Correction

Apply the factor in the table below to the calculated backwash flow to maintain ≈ 35 % bed expansion.

Water Temperature (°C)	Correction Factor
0 – 4	0.51
4 – 10	0.64
10 – 16	0.77
16 – 21	0.86
21 – 27	1.00
27 – 32	1.12
32 – 38	1.24
38 – 43	1.35
43 – 49	1.47

 

3.2 Backwash Flow Requirements

(Metric equivalent of Table III — flows are m³ h⁻¹, air at 6 psig ≈ 41 kPa(g))

Tank Ø	Bed Backwash (m³/h)(35 % expansion)	Bed Backwash + Air (m³/h)(35 % expansion)	Air Scour Rate (m³/h)@6 psig
305 mm	3.6	2.3	4.1
457 mm	8.2	5.0	9.2
610 mm	14.3	8.6	15.8
762 mm	22.3	14.3	25.0
914 mm	31.8	22.3	36.2
1,219 mm	57.2	31.8	64.2
1,829 mm	128.3	77.0	144.2

 

Notes

• Base water up‑flow for hydraulic backwash ≈ 49 m h⁻¹ (20 gpm ft⁻²).
• When air scouring, reduce water flow to 60 % of the hydraulic‑only rate and inject air at ≈ 3 Nm³ h⁻¹ m⁻² of bed area (values shown above).
• Backwash duration: 5 – 6 min per cycle.

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4. Design Formulae (Metric)

• Hydraulic backwash (m³ h⁻¹)
  Q=49×A×CTQ = 49 × A × C_T
  where A = bed surface area (m²), C_T = temperature correction factor.
• Backwash with air scour (m³ h⁻¹)
  Q=0.6×49×A×CTQ = 0.6 × 49 × A × C_T
• Air scour rate (Nm³ h⁻¹)
  Qair=3×AQ_\mathrm{{air}} = 3 × A

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5. Quick Unit Conversions

US unit	Metric equivalent
1 US gpm	0.227 m³ h⁻¹
1 ft²	0.0929 m²
1 ft³	0.0283 m³
1 ft	0.3048 m
1 psi	6.895 kPa
(20 gpm ft⁻²)	49 m h⁻¹

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6. References & Assumptions

• Data sourced from “nextSand System Design Guide” (original US‑units specification).
• All conversions rounded to two significant figures for practical use.
• Verify local water temperatures and available backwash pressure before final design.