What it does: makes drinking water at your kitchen tap, on demand, in about five inches of cabinet width.
The Cahaba Slim 800 is designed for homeowners who want strong direct-flow performance
without giving up the cabinet space required by a traditional storage tank.
TANKLESS
$1,295installed · all in equipment · labor · warranty
$1,295 including standard installation — equipment, licensed
installation, commissioning and a 12-month workmanship warranty. Priced level with the Cahaba
Signature 75, our premium traditional-tank system.
Configuration
Tankless — four-stage
Direct flow
Approximately 0.62 GPM
Recovery
Approximately 65%
Cabinet width
Approximately 5.1 in
No tankThe same cabinet, without the storage tank. Representative installation — what the tank would have occupied stays yours.
Cabinet space
The tank is the part that takes the room.
Remove the storage tank and the cabinet under your sink comes back to you.
A traditional under-sink reverse osmosis system makes water steadily and holds it in a
small pressurized tank. When you open the drinking-water faucet, the tank fills your
glass. That is how the Cahaba Pure 50 and the
Cahaba Signature 75 work, and it is a proven way to build
a drinking-water system.
The Slim 800 takes a different route. It makes water as you draw it, so the
production rate is what fills the glass — and the cabinet holds one
slim unit rather than a unit and a tank. That is why the platform figure on this system is
high and the footprint is narrow.
What you get is cabinet space, a simpler object under the sink, and water on demand at the
same published price as our premium tank system.
Configuration
Tankless — four-stage, no storage vesselThe cabinet holds the unit and nothing else.
Platform
Nominal 800 GPDGPD means gallons per day. It is the manufacturer's nominal production rate under its own test conditions.
Direct flow
Approximately 0.62 GPMManufacturer specification. With no stored reserve, this is the rate that fills the glass.
Suited to
Kitchens where cabinet space matters and water is wanted fast
Installed price
$1,295Equipment, licensed installation, commissioning and the 12-month workmanship warranty.
Under-sink configuration — tank and tankless
Schematic only
Configuration schematic. It shows which parts sit in the cabinet, not how large they are.
The measured figures are printed as numbers under
specifications, where they can be read as measurements.
Specifications
The manufacturer's numbers, printed in full.
These are manufacturer specifications for the platform we install. They describe the format,
the flow profile and the footprint — what the system is, and how much of your cabinet
it asks for.
The published specification, line by line
Format
Tankless — no storage vessel
Stages
Four-stage configurationA stage count describes how the system is built. It is not a ranking of treatment.
Nominal production
800 GPD platformThe manufacturer's nominal production rate under its own test conditions.
Direct flow
Approximately 0.62 GPM
Recovery
Approximately 65%The share of feed water that leaves the system as treated water under the manufacturer's test conditions.
Dimensions
Approximately 5.1 in wide × 15.6 in deep × 14.8 in highWe confirm the cabinet opening with you before we schedule.
Installed by
A licensed Alabama plumbing contractorSingle visit, under-sink. Nothing is added to your main water line.
Equipment manufacturer
Hydrotech / Aqua FloThe platform is built by an established equipment manufacturer and installed under our own specification and warranty.
Tankless describes the format and flow profile. It does not mean the water
is inherently “cleaner” than our traditional RO systems. Choose the Slim 800 for
cabinet space and direct-flow performance; choose a
tank system for a reserve already made and waiting.
Figures on this page are manufacturer specifications for the platform. A production rate
describes how fast water is made, and a recovery ratio describes how much of the feed water
becomes treated water. Both are useful numbers, and neither is a measure of contaminant
reduction — see what is actually in Birmingham water.
Where it fits
Four drinking-water systems. Pick the one that answers your question.
The Slim 800 sits level with the Signature 75 at the same price, answering a different question about the same cabinet.
Our drinking-water ladder has three rungs: Pure 50, Performance 75, Signature 75. The Slim 800
stands beside the third at the same published price. Same money, different
priority — cabinet space and direct flow, rather than a stored reserve.
RUNG 01 · ESSENTIAL
Cahaba Pure 50
$995 installed
Premium reverse-osmosis drinking water at our lowest installed price. It is the most
common place people start.
The ladder rises on platform and production. It is a ladder of formats and output, not a
ranking of contaminant reduction, so the four systems are presented at their published prices
and left to answer different questions.
Side by side
All four, on the record.
Every value below comes out of our own product record. Where the record is still open, the
cell says so rather than being filled in with something plausible.
All four systems compared, line by line
Cahaba Pure 50
Cahaba Performance 75
Cahaba Signature 75
Cahaba Slim 800
Installed price
$995
$1,095
$1,295
$1,295
Position
Rung 01 · Essential
Rung 02 · Performance
Rung 03 · Signature 75
Alternative, level with rung 03
Storage
Approximately 4-gallon metal tank
3.0-gallon tank
3.0-gallon tank
None — tankless
Nominal production
50 GPD
75 GPD
75 GPD
800 GPDA rate at which water is made, on this row and every other.
Stages
Four
Five
Not documented
Four
Booster pump
Not fitted
Fitted
Fitted
Not documented
What we publish about certification
IAPMO R&T certifies this configuration to NSF/ANSI 58 and CSA B483.1, including PFOA and PFOS reduction.
The manufacturer identifies the membrane and the storage tank as NSF certified, not the complete system.
The storage tank is identified as NSF certified, not the complete system.
No certification listing is published for this configuration.
Choose it when
You primarily want better drinking water, with normal household demand and adequate feed pressure.
You want higher production, or your feed pressure needs support.
You want the top traditional RO platform we offer.
Cabinet space and direct flow matter more to you than a stored reserve.
Four systems, four separate claim sets. A certification belongs to the configuration it was
issued for, and a certified part is a certified part rather than a certified system. That is
why each column is written on its own terms.
One tap, or the whole house
This is a decision about one tap.
A drinking-water system treats the water at your kitchen sink. What the rest of the house needs
is a separate question, answered from measured numbers rather than from which faucet you chose.
Treatment level answers
What does this home want or need treated?
Taste, odor and chlorine at the drinking tap, or at every tap
Hard water, where the measured figure justifies a softener
Whether a premium RO, a UV lamp or monitoring belongs in the design
What the utility's published data and your own test actually show
System size answers
How much water must this home handle at peak demand?
Service-line width and the pressure we measure at the house
Bathrooms, showers running at once, body sprays, large soaking tubs
Laundry and dishwasher demand, and other heavy-draw fixtures
Flow rate through the media, valve capacity and the backwash rinse
The manufacturer documentation we hold, and the parts of the record that are still open, in
one place. Ask us about any line here and you will get the same answer in writing.
Slim 800 — the published record Representative unit — cartridges behind the front panel, quick-connect ports at the base. The published specification is the record, not the picture.
What is documented, and where the claim stops
A tankless, four-stage configuration — manufacturer specification
Nominal 800 GPD platform — the rate at which water is made
Approximately 0.62 GPM direct flow, approximately 65% recovery — manufacturer specifications
Approximately 5.1 in wide — the reason this one fits where a tank system does not
Certification — no listing is published for this configuration. When we hold one, we print it here with the number so you can check it yourself
Certification listing
Not publishedFor contrast, the Cahaba Pure 50 carries one: IAPMO R&T certifies this configuration to NSF/ANSI 58 and CSA B483.1, including PFOA and PFOS reduction. That listing belongs to the Pure 50 configuration and stays with it.
Booster pump
Not documented
Faucet
Confirmed with you before we scheduleIn writing, along with anything about your cabinet that changes the job.
Every system we sell gets the same treatment on its own page: a documented figure where we hold
one, and a plain blank where we do not. The blanks are what makes the rest of it worth reading.
Questions
The honest answers.
How is the Slim 800 different from the Cahaba Signature 75?
Both are $1,295 installed, and they answer different questions.
The Signature 75 is our premium traditional-tank RO system, with treated water already made and
waiting in a 3.0-gallon tank. The Slim 800 removes the tank and makes water as you draw it.
Choose the Slim 800 when cabinet space and direct-flow performance matter most to you.
Does tankless mean cleaner water?
Tankless describes the format and the flow profile. It does not mean the water is
inherently cleaner than our traditional RO systems, and we publish the same treatment
documentation either way. Choose the Slim 800 for cabinet space and direct flow.
What does 800 GPD actually mean?
Gallons per day is a nominal production rate — how fast the system can make
water under the manufacturer's test conditions. It describes output, not contaminant reduction.
On a tankless system the rate matters for a specific reason: there is no stored reserve, so the
production rate is what fills the glass. The manufacturer specifies approximately
0.62 GPM of direct flow on this platform.
How much space does it need under the sink?
The manufacturer specifies approximately 5.1 in wide,
15.6 in deep and 14.8 in high. There is no storage tank, so the
cabinet floor stays clear. We confirm your cabinet opening with you before we schedule the
install.
What is the Slim 800 certified for?
No certification listing is published for this configuration. When we hold one, we
will print it here with the number so you can verify it yourself. For contrast, here is what we
publish elsewhere. Cahaba Pure 50: IAPMO R&T certifies this configuration to
NSF/ANSI 58 and CSA B483.1, including PFOA and PFOS reduction. Cahaba Signature 75:
The storage tank is identified as NSF certified, not the complete system.
Is $1,295 really the whole price?
For a standard under-sink installation, yes — $1,295 including standard
installation, commissioning and a 12-month workmanship warranty. The price is subject only to
unusual site conditions confirmed before scheduling, in writing, never on install day.
Cahaba Water Co.
