Sanavia Reverse Osmosis Carbon Block Filter
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Replacement 800G carbon block filter cartridge for Sanavia reverse osmosis water filtration systems. Reduces chlorine, chloramines, VOCs, sediment, and other contaminants for cleaner, better-tasting water.
Compatible with Sanavia RO units. Recommended replacement every 12 months depending on water quality and usage.
Features:
- 800G high-capacity carbon block filtration
- Reduces PFAS, heavy metals, and chemical contaminants
- Easy twist-and-lock installation
- Fits standard Sanavia RO housing
What this cartridge does
The Hydra runs at 800 GPD with no storage tank, which means every glass is filtered on demand rather than drawn from a reservoir that was filled hours ago. That only works if the cartridge can keep up at full flow, which is what the 800G rating is about. It is sold as reducing chlorine, chloramines, VOCs and sediment, along with PFAS, heavy metals and chemical contaminants.
What it is up against here
The contaminants below are the ones this cartridge is sold as reducing, set against what EPA and EWG data actually show in water across DC, Maryland and Virginia.
- PFAS
- EPA's most recent national monitoring round found PFAS in supplies across this region. EWG's health standard for PFOA is 0.09 parts per trillion, against a federal limit of 4 ppt that is not enforceable until 2029 — the gap between legal and safe, in one contaminant.
- Chloramines
- DC Water and WSSC both disinfect with chloramine rather than free chlorine, because it survives a long distribution network. It is also what gives treated water its flat, faintly chemical taste, and it is more corrosive to old household plumbing than chlorine is.
- Chlorine and its byproducts
- Chlorine reacting with organic matter from the Potomac is what forms trihalomethanes and haloacetic acids. Across the systems we hold EPA data for, those two sit further above EWG's health guidelines than anything else measured — and they form in the pipes after treatment, not at the plant.
- Lead
- Lead does not arrive from the treatment plant. It comes off the service line and the household plumbing between the main and the tap, which is why two houses on the same street can test differently — and why the fix has to be at the tap.
Not sure which of these are in your water? Look up your city’s testing record.
When to replace it
Replace every 12 months, per Sanavia's guidance, depending on water quality and usage.
A tankless system has no buffer, so a tired cartridge shows up as falling flow at the faucet before it shows up anywhere else. Slower fill is the signal to change it.
Questions, answered.
It is the capacity rating that matches the Hydra system's 800 gallon-per-day, tankless output. Because there is no storage tank, water is filtered at the moment you open the tap rather than pulled from a reservoir, so the cartridge has to hold its performance at full flow.
They are different stages of the same system, not alternatives. The 800G ROCB cartridge is the high-capacity stage; the carbon block cartridge is the one that handles taste, odor and disinfection chemistry. Sanavia's own guidance is to replace both together, which is what the bundle is.
Every 12 months, depending on water quality and how much water your household uses. On a tankless system, a noticeable drop in flow at the faucet usually arrives before the twelve months are up in hard-working households, and that is the better signal to go by.
Yes — it fits the standard Sanavia RO housing and installs twist-and-lock, with no tools.