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💧 Elevate your hydration game with the ultimate RO expansion tank—because clean water waits for no one!
The GTS3 3 Gallon RO Water Filtration Expansion Tank is a compact, durable, and easy-to-install solution designed to enhance your reverse osmosis system. Made from 100% food-grade, BPA-free materials and constructed with precision-welded steel, it stores up to 2.2 gallons of purified water for on-demand use. Featuring a 1/4” quick connect ball valve and universal fit, it ensures seamless integration under most kitchen sinks, delivering reliable, contaminant-free water flow with a 1-year warranty for lasting value.










| ASIN | B079YZ8THK |
| Best Sellers Rank | #61,332 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #113 in Under-Sink & Countertop Filtration |
| Brand | tankRo |
| Brand Name | tankRo |
| Capacity | 3 gallons |
| Container Type | Tank |
| Customer Reviews | 4.5 out of 5 stars 1,405 Reviews |
| Included Components | Tank |
| Installation Type | Under Sink |
| Item Dimensions L x W x H | 9"L x 9"W x 14"H |
| Item Highlight | White Finish, Includes 1/4" Ball Valve, Durable Steel Construction, Universal Fit for RO Units |
| Item Weight | 6 pounds |
| LowerTemperature Range | 33 °F |
| Manufacturer | tankRo |
| Material | BPA Free |
| Material Type | BPA Free |
| Maximum Flow Rate | 0.8 gpm |
| Model Name | GTS3 |
| Model Number | GTS3 |
| Number of Items | 1 |
| Operating Pressure Range | 5-100 psi |
| Other Special Features of the Product | Durable |
| Part Number | GTS3 |
| Power Source | Adapter |
| Product Dimensions | 9"L x 9"W x 14"H |
| Purification Method | Reverse Osmosis |
| Special Feature | Durable |
| Supported Water TDS Level Maximum (PPM) | 2000 |
| UPC | 653590999287 |
| Upper Temperature Rating | 100 °F |
J**Z
Hi, quality product top-notch.
If are struggling with low pressure? Intermittent working and slow water from the osmosis system, this is the way to go. This reserve water tank was the answer to my problem. The installation was easy, a filtration system through that is absolutely no problem. Whatsoever value for your money is on top. You can't beat the price. It is cheaper than trying to have somebody come out. And go through the system, as for the quality of the tank, it is top-notch.
F**4
Great upgrade for my RO system
I’ve had a RO system for many years and had a smaller tank on it. The bladder finally went and I decided to upgrade and it is performing very well. I followed the instructions to clear the tank after one minute of operation and then again after four hours of operation. There is no residual taste. When hooking it up to your system, I would make sure to just leave the pressure where it’s at as it is typical for most systems. If it doesn’t work for you then adjust it. Furthermore, when you put the Plastic valve on the top, I would use not only Teflon tape but also some dope as well. I had to return the first tank they sent as it was not wrapped well and came dented, but to be fair it did work for the short period of time before a replacement was sent, the company was quite responsive. As an FYI, the second tank came much better wrapped. It was undamaged. they had clearly realized they had a problem so they change the wrapping.
B**Y
Ditch that small tank for this - you will be glad you did. SO. MUCH. WATER!
Original RO system came with a paltry 3 gallon tank, of which only 1.8 gallons was for water storage. I didn't know how awful that was until the membrane in that tank died. Determined to ensure we always have enough RO and plenty of pressure in the line, I doubled the desired capacity, and then DOUBLED it AGAIN. So, the 8 desired gallons of liquid required a 10-12 gallon tank. The tank came with ZERO installation hardware. I stole the old valve from the old tank which worked out just fine. By morning, we had 8 gallons of RO water flowing. I strongly recommend this tank!
J**.
Good tank, bad hardware
This is a perfectly nice tank that is let down by the crappy hardware and fittings they installed on it. Which is unfortunate, because I wouldn't have faulted it at all for coming with NO hardware, even if it was the same price. But who wants to undo and re-do somebody else's work? The tank has a big plastic foot with a hole for the pipe. It can be installed in six positions depending on how much you have to turn the elbow on the bottom to get it to seal. Don't even bother with anything they did. Remove the whole foot, and remove the elbow. The cheapo elbow had a giant burr in the threads and didn't seal. In order to get a wrench on it you have to remove the foot. And once it's tight it's not going to be pointing the same direction it was before anyway. There is an additional chromed fitting with a dramatically undersized ball valve too.... plan on just tossing those. I _know_ it's hard to source quality stainless NPT elbows these days. But if they're going to buy garbage ones, they should at least chase the threads and/or pressure test after assembly.
A**O
Perfect fit
Fast and simple. My old tank had a bladder failure and needed to be replaced. The new tank came with the top fitting, but I drained and removed the old tank and slipped this one in without any issues because the fittings were the same.
J**N
Works great
Works as described
A**S
Good value
Replaced a smaller tank because of lack of supply. This one hold more than we would ever use. Easy to install and great price
R**D
Stopped working after 2 months
I just purchased this about 2 months ago and it was working fine. However, last night it stopped dispensing water and the tank can’t keep pressure in it. I don’t know if it has a leak or what but no matter what I do the pressure won’t hold and no water coming out. I tried contacting the seller but no luck.
K**S
I inflated the bladder in the tank to 24lb hooked it up to the pump and voila instant peace.
The tank I had on my pump was too small, so my pump was always starting. I installed this big boy and now I can take a shower without it starting. Other than the possibility that the inlet may have a smaller pipe than your present tank, necessitating the purchase of a couple of pipe fittings, this tank is the answer to your problem. Don't forget to inflate the tank to withing two pounds of the kick-in setting on the pump. 24 p.s.i. is fine on such a big tank. The air pressure valve is under a 1" cap on the tank. Enjoy
W**9
Fantastic product, right price, fast delivery ❣️
This is without a doubt the best value for my money ever. It arrived fast and in impeccable condition. It was double boxed and had sufficiently been secured. I had no problems following the easy installation instructions. We now have a larger storage tank on our RO system and are enjoying it again. In my mind this is a must have replacement tank for your RO system, high quality, fast delivery, easy installation, easy instructions and most of all, the right price❣️
S**K
Good product
Works and easy to install, Water doesn't smell plastic I have a lot of water to fill up every bottle
S**N
Great tank but connection not as expected
This is a great water tank but beware the tank comes with a 1 inch NPT female to 3/4 inch male 90 on the bottom of the tank. Not sure why they did this. Most tank Tee Kits are 1 inch male NPT. You will need to purchase a 1 inch NPT female to female 90 to connect it to your tank tee.
G**E
tank to supplement existing RO system
I ran a new line to my fridge's water dispenser and ice maker from my existing 3 gallon reverse osmosis system. The existing tank was barely enough to keep up with my family of 4, but this will help supplement. It was installed in parallel with the other tank. The tank comes with a 1/4" tank valve. My existing system is mostly 3/8" so I had to purchase an extra valve for it. Pros: the tank came pre-charged to 7psi. I received a 6.5 gallon tank instead of 6. The tank was a nice blue as pictured. Cons: the tank came with a dent at the top.
Trustpilot
3 weeks ago
3 days ago