SIDE BY SIDE
See prices, running costs, specifications and trade-offs side by side. Choose two to four products of the same type.
Under sink reverse osmosis
RO500AK-BN tankless, 500 GPD, 2:1 pure-to-drain ratio, 3-stage with alkaline remineralization, brushed nickel faucet; system only, without the UVF8 UV add-on
$692.99US price, checkedTankless 500 GPD reverse osmosis with an alkaline stage, NSF 58 certified for TDS
Check price at iSpring for iSpring RO500AK-BN Tankless Reverse Osmosis System Full review →
Under sink reverse osmosis
ROES-50 Essence 5-stage, 50 GPD
$230.99US price, checkedCheap tank RO with low filter costs and output that depends on your water pressure
Check price at APEC for APEC ROES-50 Full review →| Criterion | iSpring RO500AK-BN Tankless Reverse Osmosis System | APEC ROES-50 |
|---|---|---|
| US price | $692.99Checked Oct 13, 2026 · Price details in the review | $230.99Checked Oct 13, 2026 · Price details in the review |
| Three-year ownership estimate | $1,202.99 Incomplete known subtotal. Not included: installation, energy use. | $395.90 Incomplete known subtotal. Not included: installation. |
| Choose if | A kitchen with under-sink plumbing and a drain, if you want tankless RO with minerals added back. | You want RO water at one kitchen sink for little money, and your water pressure is near 60 psi. |
| Main trade-off | Filters run about $170 a year on the 2-year pack, the product page doesn't give power needs, and opened returns lose 15% plus return shipping. | WQA lists 34.8 GPD and TDS reduction. APEC's 50 GPD at 60 psi and 30 GPD at 50 psi are separate manufacturer ratings, not a basis for assuming lead or PFAS certification. |
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| Exact variant | RO500AK-BN tankless, 500 GPD, 2:1 pure-to-drain ratio, 3-stage with alkaline remineralization, brushed nickel faucet; system only, without the UVF8 UV add-on | ROES-50 Essence 5-stage, 50 GPD |
| Dimensions | 17.5 in L × 5.12 in W × 16.25 in H and 25.0 lb, per the product page. iSpring doesn't say how much clearance you need for filter changes. | System 15.5 in L × 5.25 in W × 17 in H. Tank 11 × 11 × 15 in. Package weight 26 lb. The manual says to allow about 17 × 6 × 18 in for the system and 11 in across and 18 in tall for the tank. |
| Installation | It goes under the sink, and the product page calls installation DIY. A feed water adapter fits 1/2 in or 3/8 in supply pipes, and the product title names a brushed nickel faucet. Because it's a reverse osmosis system, it sends reject water to a drain, at a rated 2:1 pure-to-drain ratio. The product page doesn't give the drain connection hardware, faucet-hole size, operating pressure range or power requirements. iSpring says you can change filters in seconds without shutting off the water supply. The refund policy says the warranty doesn't cover installation costs. | APEC sells it as a do-it-yourself install and links a general RO installation video. It connects to the cold-water line only, using the included 1/2 in feed adapter and valve. You drill a 1/2 in hole for the standard faucet (1-1/4 in for an air-gap faucet) and a 1/4 in hole in the drain pipe for the drain saddle. Tubing is color-coded with quick-connect fittings. Feed water must be 40 to 85 psi, 40 to 100°F, under 2,000 ppm TDS and pH 2 to 11. The warranty doesn't cover damage from installation. |
| Materials | It has three stages. First comes a 2-in-1 composite sediment and carbon block filter (FCF500), listed as PP and CTO. Next is the RO membrane (MRO500). Last is a carbon alkaline filter (FCA500), which the page describes as coconut-shell activated carbon with minerals. iSpring doesn't list housing, tubing or faucet materials. | Five stages: a 5-micron polypropylene sediment filter, two 10-micron carbon block filters, a high-rejection TFC RO membrane and a 10 in coconut-shell refining carbon filter for taste. The kit includes a lead-free faucet, food-grade tubing, a stainless steel check valve and a flow restrictor. APEC doesn't state the tank's material. |
| Warranty | The product page lists a one-year manufacturer warranty, and the refund policy fills in the terms. It covers defects in materials and workmanship for one year from the date of purchase. You must register at ispringfilter.com to be eligible. It applies only to products bought from an authorized iSpring dealer or reseller. The only remedy is repair or replacement, at iSpring's option. A repaired or replacement product is covered for the rest of the original period or 6 months, whichever is longer. Installation and reinstallation costs aren't covered. The product page mentions an extended warranty on registration but doesn't give its length or terms. iSpring also lists lifetime phone and technical support from Atlanta, GA. | One year from the purchase date, covering defects in materials and workmanship. Used filter cartridges and membranes are excluded. It's void if you aren't the original purchaser, or if you run it outside normal municipal or well water conditions. The manual also voids it if you bought the unit used or from anyone other than APEC or an authorized dealer. Coverage depends on changing filters as the manual directs, and damage from non-APEC parts is excluded. A claim needs a return goods authorization number, and you pay to ship the unit to APEC. APEC's FAQ promises lifetime technical support. |
| Returns | The product page lists a 30-day money-back guarantee, but the refund policy attaches conditions. A full refund within 30 calendar days of purchase applies only to a product in its original packaging that hasn't been used or damaged. Open-box items within 30 days are refunded minus a 15% restocking fee. They qualify only if they aren't defective, include all parts, and are unused, undamaged and in good working order. Later returns are prorated. Unopened items get 85% back at 1 to 3 months, 65% at 3 to 6 months and 50% at 6 to 12 months. Open-box items get 70% at 1 to 3 months and 50% at 3 to 6 months. Unopened items can't be returned after 12 months, and open-box items after 6 months. You pay return shipping unless the item is defective. For a defective item, iSpring provides a prepaid label and refunds in full once the defect is confirmed. Customers in Hawaii, Alaska, Puerto Rico and outside the US pay shipping and any destination charges. Every return is subject to inspection and approval. The policy doesn't say whether an installed system counts as used. | You can return it within 30 days of the invoice date with an RMA number, and it must reach APEC within 15 days of the RMA. You get a full refund, less shipping and handling, only if it's unused in unopened packaging. Opened but unused costs a 10% fee, missing parts or damage 15% to 45%, and used but not defective 50%. You pay return shipping unless the return is APEC's error or a defect. The policy covers only orders from apecwater.com. |
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These comparisons use published specifications, not head-to-head tests. Prices and terms are dated. Unknown costs are not zero. Check the exact variant before you buy.