Nelsen Aqua Classic Reverse Osmosis
Proven under-sink RO with a pressurized storage tank.
The Aqua Classic is a traditional under-sink RO from Nelsen — blue filter housings, a pressurized 3.2-gallon steel storage tank, and up to 99% rejection of contaminants like chlorine, VOCs, fluoride, lead, arsenic, nitrates, and heavy metals. Optional booster or permeate pump for homes with low water pressure, and an ECF extended-contact carbon module for extra taste and odor polishing.
Anyone tired of bottled water bills or the taste of tap water, and homeowners who want a proven traditional RO with a storage tank ready to go.
What you get
- Removes up to 99% of taste, odor, VOCs, fluoride, arsenic, lead, and nitrates
- Pressurized 3.2-gallon storage tank — glass ready when you are
- Automatic shut-off valve eliminates wastewater when the tank is full
- Chrome long-reach faucet included (multiple finishes available)
- NSF-certified 5-micron sediment pre-filter and carbon block post-filter
- Optional booster pump for low-pressure homes or higher rejection
- Optional Aqua Classic II adds a 5-micron GAC carbon pre-filter for city (chlorinated) water
- Refrigerator / ice-maker hookup available
Specs at a glance
- Rejection
- Up to 99% of listed contaminants
- Storage tank
- 3.2 gallons, pressurized
- Certification
- NSF/ANSI 42 (materials)
- Filter change
- Pre/post-filters yearly, membrane 2–3 yrs
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DetailsNelsen Aqua Classic Reverse Osmosis — common questions
What buyers ask us before they choose this system.
How does reverse osmosis work?
Water is pushed through a semipermeable membrane that blocks dissolved solids, nitrates, lead, and most contaminants while letting water molecules through. Pre-filters catch sediment and chlorine before the membrane, and a carbon post-filter polishes taste on the way to the faucet. Filtered water is held in a small tank under the sink so it's there when you need it.
How often do RO filters need changing?
Pre-filters and carbon post-filters are annual on most systems. The membrane itself lasts three to five years, longer if the water is softened first — hardness is the main thing that shortens membrane life, which is why we usually recommend the softener and RO together.
Does reverse osmosis remove nitrates from well water?
Yes, and that's a real consideration in agricultural parts of the Magic Valley where nitrate levels in private wells can exceed the 10 mg/L drinking water standard. RO is one of the few point-of-use technologies that reliably reduces nitrates. If you're on a well and haven't tested for it, we'll include it in your free water test.
Can RO be plumbed to the refrigerator ice maker?
Yes — that's one of the most requested add-ons. We run a dedicated line from the RO tank to the fridge so ice and chilled water come from the same filtered supply. It's a straightforward addition during install and can be retrofitted later.