SLF Water Filtration Comparison · 2026
APEC RO-PH90
Recommended for shoppers who prefer proven traditional RO hardware but want higher 90 GPD output and alkaline remineralization.
VIVA21 5-Stage RO
Recommended for shoppers seeking an affordable traditional under-sink RO system with stronger certification positioning than many budget alternatives.
VIVA21 5-Stage RO
Choose the VIVA21 5-Stage for low purchase and maintenance costs.
RO Performance & Ownership
Compare RO output, filtration stages, remineralization, contaminant evidence, certifications and ownership cost.
Which Is Right for You?
APEC RO-PH90
Best for: Homeowners wanting broad reverse-osmosis contaminant reduction plus minerals added back for taste and pH, without moving to an electronic tankless system.
Consider if: Want Remineralization
VIVA21 5-Stage RO
Best for: Budget-conscious households that want a conventional, certified-positioned under-sink RO system with a storage tank and standard-size replacement filters.
Consider if: Budget Under $200, Low Replacement Cost
Our Recommendation
APEC RO-PH90
A strong premium traditional RO choice for households that want alkaline remineralized water and established certification without electronics or a tankless design.
VIVA21 5-Stage RO
A strong budget-oriented conventional RO choice for households that have cabinet space and value certification and standard replacement filters over high output and connected features.
The Short Answer
Choose RO-PH90 for 90 GPD plus alkaline remineralization and WQA Gold Seal certification.
Choose the VIVA21 5-Stage for low purchase and maintenance costs.
Water Filter Comparison FAQs
Answers are generated from the current SLF product records for these two systems.
Which is better, APEC RO-PH90 or VIVA21 5-Stage RO?
VIVA21 5-Stage RO is the overall pick for this specific matchup. Choose the VIVA21 5-Stage for low purchase and maintenance costs.
Which system has the higher daily filtration capacity?
APEC RO-PH90 has the higher rated output: 90 GPD versus 50 GPD.
Which system offers remineralization?
APEC RO-PH90: Yes. VIVA21 5-Stage RO: No.
Which system has the lower MSRP?
VIVA21 5-Stage RO has the lower MSRP in the current SLF records at $289.99, compared with $409.99 for the other system.
Do both systems require a plumbing connection?
APEC RO-PH90: Yes. VIVA21 5-Stage RO: Yes.
Which system is more renter friendly?
APEC RO-PH90: No. VIVA21 5-Stage RO: No. Check lease and plumbing-modification rules before installing an under-sink system.
What certifications are listed for these systems?
APEC RO-PH90: APEC RO-PH90 is WQA Gold Seal certified to NSF/ANSI 58. The certified reduction scope includes lead, fluoride and other specified contaminants. Broader APEC claims covering 1,000+ contaminants should be treated separately as manufacturer claims unless included in the applicable certification or performance data. VIVA21 5-Stage RO: Filter United identifies exact model V21RS5S01 as WQA Gold Seal certified to NSF/ANSI 58 for reverse-osmosis system performance and NSF/ANSI/CAN 372 for lead-content compliance. SLF has not independently located the exact model in WQA's searchable public directory, so retain the manufacturer-source qualification until the directory record is captured.
How do estimated annual filter costs compare?
APEC RO-PH90: $74.99. VIVA21 5-Stage RO: $60.00. Actual replacement timing and prices can vary.