Bio Bidet A8 vs 6800/6800U: Is it Worth Paying Extra?

Today we’re comparing two Bio Bidets, the A8 Serenity and the USPA 6800/6800U. For more in-depth info on the 6800 (with images and demos), check out the Bio Bidet 6800 vs 6800U review and comparison (article link).

The A8 Serenity combines features of the USPA 6800U and Ultimate 770 into one bidet. For example, it has a double-sided remote and auto function (6800U), as well as a stainless-steel wand and higher-quality water heater (Ultimate 770). Overall, the 6800U still provides way better bang for your buck. 

This is one of those instances where paying for the fancier bidet doesn’t really get you much in the way of added features.

The A8 is a higher-tier bidet (at least it’s marketed that way), but not enough to warrant the price difference, in my opinion.

Plus, it’s not typically carried at retailers like Amazon, so folks usually get it direct from Bio Bidet, making it even more expensive. However, at Bidet King you can often find it for much less than directly from the manufacturer.

Quick note: in saying that the 6800 is the better option for the money, I’m talking about the newer version which you can find here (Amazon link). Not the original. When compared to the older version of the 6800, the A8 Serenity is the clear winner.

Here are some of the main differences:

  • The A8 Serenity has a better water heater. 
  • Special enema function with the USPA 6800 and 6800U. 
  • Fancier wireless remote with 6800U. 
  • Dual nozzles vs single dual-action nozzle. 
  • Stainless-steel vs plastic cleaning wands. 
  • Automatic vs on-demand self-cleaning function. 
  • No enema mode with the A8 Serenity 
  • In my experience, the A8 Serenity costs more. 
  • The classic USPA 6800 doesn’t have user presets or nightlight. 

Quick note: for more options in USPA 6800 price range, see this article. For more options like the A8, see this article. You’ll find a side-by-side comparison of premium and luxury class bidets, most of which offer more for the money than either the USPA 6800U or A8 Serenity.

Bio Bidet 6800/6800U vs A8: Quick Comparison Table 

Feature(s)BB USPA 6800/6800UBB A8 Serenity
Available in Elongated and RoundYY
Water Heater TypeRegular Tank-TypeAdvanced Hybrid-Type Heater
Warm Air Dryer w/Adjustable TempYY
Heated Seat w/Adjustable TempYY
Handheld Remote6800U: Double-Sided Wireless Remote w/LCD Screen

6800: Wireless Remote w/LCD Screen
Double-Sided Wireless Remote w/LCD Screen
Air DeodorizerYY
Wand MaterialPlasticStainless Steel
Nozzle Design for Posterior and Front Feminine HygieneDual NozzlesSingle 2-in-1 Nozzle
Adjustable Nozzle Position for Accurate Aiming5 Positions5 Positions
Wand Self-Clean FunctionAutomatic Self-CleaningOn-Demand Self-Cleaning
Child Wash Mode
User Presets
(Save Your Preferred Settings)
6800U: 2 Users; Front and Rear; Nozzle Position and Water Pressure

6800: None
2 Users; Front and Rear; Nozzle Position and Water Pressure
Easy Auto Function
(One-Push Operation)
Bowl-Illuminating Night Light6800U: Y

6800: N
Adjustable Water Temperature and PressureYY
High-Pressure Turbo ModeY (Enema Mode)N
Water Pressure
(Flow Rate)
0.9 L/min or ~0.24 gal/min0.7 L/min or ~0.18 gal/min
Nozzle Oscillation
(Back-and-Forth Spraying)
Nozzle PulseYN
Aerated Wash YY
Slow-Close Seat/LidYY
Quick-Release Seat/LidYY
Power-Saving Eco Mode(s)YY
Aesthetics Less Bulky (5.4″ Rear Height vs 6.8″)Lower-Profile (Solid White, No Decals, Etc.)
Safety Seat SensorYY
PriceThe 6800U = Best Value (~20% Less than the A8 w/mos of the features).

Original 6800 = Worst Value
Choose Only if Longer Warm Water Is a Priority

Main Differences: Bio Bidet 6800/6800U vs A8 

The A8 Serenity Has the Best Water Heater  

Expect longer warm water flow with the A8 Serenity compared to the USPA 6800/6800U. 

In case you’re new to the subject, bidet water heaters come in a few types: tank (or reservoir-type), enhanced reservoir, tankless, and hybrid heaters.  

Tank-type heaters are the least sophisticated, running cold once the tank empties at about 40 seconds.

Tankless heaters are instantaneous, so they provide endless warm water at max temp. Luxury bidets like the Discovery DLS have this kind. 

Hybrid heaters use both heated reservoir and instantaneous heating technology to provide endless heated water. Mid-tier (premium) bidets tend to have hybrid heaters. The water remains at max temp for about 40 seconds and then dips in temperature but remains warm indefinitely.

The hybrid heater of the A8 is above average hybrid heater that keeps the water at a higher temperature once the tank runs out.

Advanced reservoir heaters are similar to hybrid heaters but the water tends not to be as warm. The USPA 6800/6800U has this type of heater. The heated reservoir on the USPA 6800U holds 2 to 2-½ cups, and you can expect about 40 seconds of warm water at max temp (~100 F) before the temp drops to about 90 F.

The A8 Serenity Lacks a Turbo or Pulse Mode 

Don’t get me wrong, the water pressure with the A8 Serenity isn’t bad. It reaches a max flow rate of 0.18 gallons per minute (or ~0.7 L/min). 

But most bidets in this price range offer an extra-strong spray mode usually labeled “turbo”.

Like all modern bidets, the A8 has several pressure settings—5 levels which is the standard. But there’s usually some sort of high-pressure setting achieved by an extra-narrow nozzle hole to get a more concentrated spray. 

This brings us to the next point. 

The 6800 and 6800U Has a Special Enema Mode  

On top of the max pressure setting, the USPA 6800/6800U has a high-pressure setting meant to help relieve constipation. It’s called the IPP setting which stands for Intensive Impulse Pulsation. 

It’s marketed as an enema function but doubles as a general high-pressure wash setting.  

The IPP setting pulses high pressure to massage the sphincters, which is known to help stimulate bowel movements (source). 

Dual Nozzles vs Single 2-in-1  

Like all modern bidets, the USPA 6800/6800U and A8 Serenity have both front and rear spray settings, so they can be used for regular and feminine hygiene.

The USPA 6800/6800U does this with two nozzles, one for the front and the other for posterior cleaning. The A8 Serenity does it with a single 2-in-1 nozzle (two holes in one nozzle).  

In my experience, it makes very little difference. If I were choosing a bidet solely on this feature, I suppose I’d go with the 2-in-1, because it’s fewer moving parts. But overall, it’s not something I weigh too heavily. 

The A8 Serenity Has a Stainless-Steel Nozzle  

So, the USPA 6800 and 6800U come with dual plastic nozzles while the A8 comes with a single stainless-steel wand.  

A stainless-steel nozzle is usually considered more desirable and is thus more common with premium and luxury bidets.  

That’s not always the case. For example, TOTO makes what most consider to be the highest-quality and most luxurious bidets on the market, but all their units have plastic nozzles. 

But anything made of stainless steel is bound to last longer than something made of plastic.

The 6800 and 6800U Have a Better Self-Clean Nozzle Function  

The nozzles on the 6800/6800U automatically clean themselves before and after each use, taking the responsibility off of the user. Of course, you can still clean the nozzles on-demand when you feel like it or when you notice they’re soiled. 

The A8 Serenity has an on-demand nozzle-clean function only.

I prefer automatic self-cleaning nozzles because I’m naturally forgetful. I used a non-electric bidet for a time and usually forgot to clean the nozzle—the self-cleaning nozzles on non-electric bidets always operate on-demand. 

The Classic USPA 6800 Doesn’t Have User Presets or a Nightlight  

Both the USPA 6800U and A8 Serenity come with a built-in toilet-illuminating nightlight, but not the original 6800. This feature brightens the bathroom just enough to use the toilet without having to turn the blinding bathroom lights on. 

You can find a regular nightlight at pretty much any retail store. But for this purpose, it would need to be plugged in close to the toilet, which isn’t always possible. So, bidet nightlights are pretty popular. 

Another feature lacking in the original USPA 6800 is user presets, or the ability to save personal settings. So, with the original 6800, the user has to hit the same buttons every time (it’s a hard life, right?).  

The user presets with the USPA 6800U and A8 Serenity operate the same: both allow 2 users to save their preferred nozzle position and water pressure. Kind of underwhelming, I will say. IMO, good user presets let you save settings for water/seat/dry temp, and session duration for washing and drying. But this version is better than none.

Features and Specs: Bio Bidet USPA 6800/6800U vs A8 

The BB USPA 6800U 

BioBidet USPA 6800U Adjustable Bidet Toilet Seat with Wireless Remote, Dual Nozzle, User Presets and Dryer, White, Elongated

First up is the Bio Bidet USPA 6800U. It’s typically less expensive than the A8, but you can check the current price here (also on Amazon). 

The 6800U is an improved version of the original 6800, in that it has a fancier remote control, user presets, and a built-in bowl-illuminating nightlight. The original 6800 is discontinued and those that are left cost more than the 6800U despite having fewer features.

It’s probably the best Bio Bidet you can get for the money.  

It offers a warm air dryer, heated seat, sleek double-sided remote control with LCD display, an adjustable nozzle for accurate aiming, dual nozzles for front and rear cleansing, automatic self-cleaning wands, oscillation and pulse modes, and an enema function. 

The enema function is great for getting things moving again when you’re backed up. It massages the sphincters to stimulate bowel contraction and can be used to let water enter the rectum to loosen things up. 

The only real downside is the tank-type heater. The 6800U heater stores about 2-½ cups of water in a heated reservoir to be used on-demand. It’ll supply warm water for about 40 seconds, at which point the water will gradually cool off, typically running cool after the minute mark. 

It may not sound like long, but that’s about twice the length of what’s needed for a typical bowel movement. It’s mostly an issue for those who want to have long sitz bath-style cleansing sessions. 

It can also be a problem if several people use the bidet since time will be needed between sessions to refill and reheat the water supply. 

Even in the event it runs out, it’s not like the bidet leaves you hanging mid-wash. Room temp water cleans just as effectively as warm water.  

Features and Specs 

Water Temperature: 

  • Tank-type heater for ~1min of warm water per session.  
  • Water temperature adjustable across 4 settings, with the highest setting reaching 104° F. 

Water Pressure: 

  • Water pressure adjustable across 5 levels, with a max flow rate of 0.24 gal (or ~ 0.9 L) per minute. 
  • A strong, high-pressure IPP (Intensive Impulse Pulsation) wash mode. 

Comfort, Convenience, and Aesthetics: 

  • Adjustable warm air dryer w/5 temperature levels.  
  • Adjustable heated seat w/4 temperature levels. 
  • Double-sided wireless remote control with LCD display screen, scratch-proof surface, and wall mount.  
  • Built-in air deodorizer to eliminate embarrassing odors.  
  • Two user presets to save personal preferences for nozzle position and water pressure.  
  • One-push auto wash feature for easy bidet operation. Press “Auto” and get 20 seconds of cleansing spray, 20 seconds of standard oscillating spray, 20 seconds of rhythmic-massage spray, and 3 minutes of drying. 
  • The bidet is non-bulky and comfortable with plenty of room up front. The design is sleek for a Bio Bidet at only 5.7” (~14.5 cm) high in the rear of the seat.  
  • The 6800U offers an aerated wash infused with microbubbles. 

Seat and Lid: 

  • Hydraulic, soft-close seat/lid to prevent wear over time. 
  • Quick-release button for easy bidet removal and cleaning. 

Cleaning Wand and Spray Capability: 

  • Dual plastic nozzles, one for regular (posterior) and the other for front feminine cleansing.  
  • Both nozzles are adjustable across 5 positions for accurate aiming. 
  • Basic oscillating spray pattern. When activated, the nozzle moves back and forth to hit a wider area. 
  • Massage-cleanse mode. When turned on, the nozzle oscillates in a regular rhythm for a massage-like effect. 
  • The nozzle can pulse water pressure.   
  • The IPP enema wash mode helps relieve constipation and doubles as a general high-pressure turbo mode.  

Safety and Sanitation: 

  • The USPA 6800U has automatic self-cleaning wands, meaning the nozzles self-clean on their own before and after each use. The nozzles can be cleaned on-demand as well. 
  • Soothing nightlight for safe night time bathroom navigation. 
  • A safety sensor to help prevent accidental bidet operation. 
  • A wash mode for kids. A kid can hit a single button for an automatic wash/dry cycle with all of the features adjusted to be child-friendly (extended nozzle, lower pressure and temperature).  

Water and Energy Efficiency: 

  • The 6800U has a lower-efficiency water heater but helps save energy with an Eco mode. The energy saver function reduces the seat and water temperature when you’re not using the bidet. 
  • The spray incorporates small air bubbles, making the 6800U one of the more water efficient bidets. 

The Bio Bidet A8 Serenity 

Bio Bidet A8 Luxury Class Bidet Toilet, Dual Sided Wireless Remote, Adjustable Heated Seat, Warm Water, Air Dryer, Stainless Steel Nozzle, Elongated

Next is the Bio Bidet A8 Serenity. You can check here for the current price (affiliate link). Amazon tends not to carry the A8 (check here if it’s available now), so I recommend Bidet King, which is a trusted vendor.

The main benefits of the A8 over the USPA 6800U include the higher-quality water heater and the stainless-steel nozzle. It also looks better, if that matters. It has a lower-profile appearance, looking more like a regular toilet seat.  

The A8 has a hybrid water heater that claims “limitless” warm water. From the feedback I’ve gotten, the warm water supply is described as prolonged. I.e., it’s not the endless warm water you get from instantaneous heaters that come with bidets like the BB Discovery DLS (their top-of-the-line bidet). 

Of course, the A8 has all the features you’d expect in a premium bidet, like a warm air dryer, wireless remote, heated seat, positionable self-cleaning nozzle, air deodorizer, nightlight, aerated spray, and a nozzle oscillation function.

Let’s cover the features, in detail. 

Features and Specs 

Water Temperature: 

  • Advanced hybrid heater for longer warm water flow. The tank holds 740 mL. With a flow rate of 7 L/min, you can expect a minute of warm water before the temperature starts to decrease slowly. With the hybrid heating technology, you’ll get an indefinite supply of lukewarm water after the tank runs out. Keep in mind, even a minute is plenty enough for most cleaning sessions. 
  • Adjustable water temp w/4 settings: “Off”, low, medium, and high, with the highest of 102° F 

Water Pressure: 

  • Adjustable pressure w/5 settings with a max of 0.18 gal (or ~0.7 L) per minute. 
  • There’s no strong wash setting (or turbo or enema mode, etc.). 

Comfort, Convenience, and Aesthetics: 

  • With the A8 Serenity, you get a sleek dual-sided remote control similar to the one that comes with the 6800U. With controls on both sides and the LCD screen, you can do a lot more with fewer buttons, hence the slim design. You can control everything from the water pressure to the volume of the chimes.  
  • Warm air dryer w/adjustable temperature. 
  • Comfy heated seat with 4 temperature settings. 
  • Dual user presets: two people can save their preferred nozzle position and water pressure for both rear and front feminine cleansing. Both the A8 and 6800U have this feature, but not the original 6800.  
  • Another convenience feature is the auto function. Just press “Auto” during normal operation of the “Cleansing” function, and you’ll get a 1-min wash (20 sec regular cleansing, 20 sec of oscillating spray, and 20 sec of massage mode) followed by a 3-min drying session. 
  • Hideaway installation feature. This is a feature that’s hard to appreciate until you get the bidet. Basically, it helps make installing the bidet easier and makes for a cleaner look. The feature centers the power cord in the back so you can swing the cord to either side, depending on where the socket is. Built-in clips keep the cord against the bidet for a nice fitted look.  
  • The water flow is aerated so it’s extra soft and comfortable. The nozzle and pump incorporate air into the water stream as small bubbles for a foamier, softer wash. 
  • The A8 Serenity is one of a handful of Bio Bidets to have a built-in deodorizer. A fan at the back of the seat pulls air through a carbon filter to break down smelly molecules


  • The bidet is kind of high in the back at 6.8” (~17.3 cm), but it’s not overly sloped so there’s plenty of room up front.  
  • Aside from the rear height, it’s one of the lower-profile Bio Bidets, because it’s a solid color—white like a normal toilet seat—and lacks any noticeable stickers or decals. 

Seat and Lid: 

  • Gentle-closing seat and lid.  
  • Quick-release side button to easily remove the bidet from the toilet for periodic cleaning. 

Cleaning Wand and Spray Capability: 

  • Single, 2-in-1 stainless-steel nozzle for posterior (regular) and front feminine cleaning. 
  • Nozzle adjustable to 5 positions for accurate aiming. 
  • Oscillating spray setting: the nozzle automatically moves back and forth to provide better coverage without the user having to shift body positions. 
  • Massage-clean mode: the oscillating nozzle moves rhythmically to provide a massage effect. 

Safety and Sanitation: 

  • On-demand self-cleaning nozzle. Just hold the rear cleansing button down for 2 seconds, and the nozzle will extend and clean itself for 30 seconds before returning to its housing. 
  • The A8 has a soothing blue nightlight making it easy to use the toilet at night without turning the blinding bathroom lights on.  
  • Intelligent body sensor to prevent accidental bidet operation. 
  • A kid wash mode. By pressing “Kids”, the user gets a 2-min cleansing session + 3min of drying with all of the settings set to child-friendly automatically. So, kids can get a quality clean with one push of a button without having to know which settings to choose.  

Water and Energy Efficiency: 

  • Energy-saver Eco mode. Pressing “Eco” for 2 seconds activates a setting that keeps the seat and water temperature set to low/room temp to cut down on power use. 
  • The aerated wash allows the bidet to use less water.  
  • The hybrid-type water heater is more efficient than the tank-type heater of the 6800 and 6800U.  

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