AMI Direct Flow 600 GPD Tankless Reverse Osmosis System (RO-DF600)
An under-sink reverse osmosis unit with a booster pump and no storage tank, $578.80 at WaterAnywhere on 2026-09-30.
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QUICK VERDICT
The AMI Direct Flow is an under-sink reverse osmosis unit that filters water while the faucet runs. WaterAnywhere, AMI's distributor, lists it at $578.80.
- Best for
- Kitchens on municipal water with an outlet and a drain under the sink, room for a cabinet 16.5 in high and 17.5 in long, and an owner who wants reverse osmosis at the tap without a storage tank.
- Skip if
- You want an NSF listed system or a published contaminant test report; your supply is of unknown quality, which the manual says needs disinfection before or after the system; you want a filter life indicator, TDS display or leak shut off, none of which AMI describes; or you need longer than the store's three month warranty.
- Tier
- Mid
The AMI Direct Flow, part number RO-DF600, is made by Applied Membranes, Inc. of Vista, California, and sold by WaterAnywhere, which calls itself the exclusive authorized distributor of AMI products. One enclosed cabinet holds a 5 micron sediment filter, two activated carbon block filters and a thin film composite membrane. A 24V DC booster pump starts when the faucet opens and shuts off when it closes. The manual lists total power consumption at 60 W and says the unit produces no water during a power cut.
AMI rates the system at 600 GPD, or 25 gallons per hour, a figure the manual bases on 750 ppm TDS tap water at room temperature. The membrane named for it, M-T3012A500, is sold on its own page as a 500 GPD part under different test conditions, and the brand does not explain the gap. Stages are counted two ways as well: 4 on the product page, 3 in the manual, which groups the carbon filters.
The removal figures are the brand's own and disagree. The product page says up to 99% of total dissolved solids and names arsenic, lead, fluoride and radium among others; the manual says up to 99.9%; the membrane page gives 96% minimum and 98% stabilized salt rejection. The product page lists chloramine for the carbon stages, which the manual omits. No test report or performance data sheet is published, and no NSF certification is claimed for this unit.
The manual wants a cold supply line with a 1/2 inch nipple, a drain and an outlet each within 9 ft, plus a pre-drilled 1/2 inch countertop hole for the supplied faucet. Its specification table sets feed pressure at 4 psi minimum and 60 psi maximum, while its operating notes say the unit does not start below 5 psi. The drain ratio is not published.
The published upkeep figures disagree. A gallery image shared with other AMI systems puts home RO maintenance at under $99 per year; the one year kit for this model is $154.34.
A unit that has been installed or had water run through it is not returnable without a verified defect, and non-defective returns carry a 25% restocking fee. The refund policy gives 30 days from delivery to request an RMA; the returns page asks for returns shipped within 7 days of receipt.
Kitchens on municipal water with an outlet and a drain under the sink, room for a cabinet 16.5 in high and 17.5 in long, and an owner who wants reverse osmosis at the tap without a storage tank.
You want an NSF listed system or a published contaminant test report; your supply is of unknown quality, which the manual says needs disinfection before or after the system; you want a filter life indicator, TDS display or leak shut off, none of which AMI describes; or you need longer than the store's three month warranty.
Specifications
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Where this fits
WaterAnywhere Direct Flow, RO-DF600 cross-shops across several editorial surfaces on this site: the full brand catalog and the in-depth guides for its category.
WaterAnywhere Direct Flow, RO-DF600 - buyer FAQ
How much does the AMI Direct Flow tankless RO system cost?
WaterAnywhere listed the AMI Direct Flow, SKU RO-DF600, at $578.80 on September 30, 2026, as a single in-stock variant with no compare-at price or sale shown. Plan for upkeep on top: the store's one year replacement kit for this model is $154.34.
Does the AMI Direct Flow need an outlet and a drain under the sink?
Yes, both. The booster pump runs at 24V DC from a mains input rated 100 to 250 V AC, and the manual says the unit makes no water without electricity. Reject water runs to a drain pipe, which must sit within 9 ft of the unit and must not be downstream of a garbage disposal.
Is the AMI Direct Flow NSF certified?
No NSF or WQA certification is claimed on the product page, in the manual or in the gallery. NSF's drinking water listings for Applied Membranes, current as of September 30, 2026, show UV systems under NSF/ANSI 55 and 1812 membranes of 24 to 100 GPD as components under NSF/ANSI 58. Neither RO-DF600 nor its M-T3012A500 membrane appears there.
How often do the AMI Direct Flow filters need replacing?
The manual gives every 3 to 6 months for the sediment and carbon filters and every 12 months for the membrane and flow restrictor. The replacement kit page words it as 6 month and 12 month service. That kit holds 2 sediment filters, 4 carbon filters, one membrane and one flow restrictor, 8 items in all.
Can I return the AMI Direct Flow if it does not fit my cabinet?
Only unused and uninstalled, unless a verified defect falls under the warranty. Non-defective returns carry a 25% restocking fee and you pay return shipping. The refund policy allows an RMA request within 30 days of delivery, but the separate returns page says returns must ship within 7 days of receipt. Measure first: the manual gives 17.5 in long, 9.6 in wide, 16.5 in high.
AMI Direct Flow 600 GPD Tankless Reverse Osmosis System (RO-DF600)
$578.8 · Verified 2026-09-30
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