Aquatic Life RO Buddie 4-Stage Aquarium Water Filter System, Reverse Osmosis RO/DI Filtration Unit for Fish Tank, Fountains, and More, 50 GPD (Gallons Per Day)
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Availability:
In Stock.
Arrives
Friday, Jun 26
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Size: 50-Gallon Four stage
Features
- CLEAN, FILTERED WATER FOR AQUARIUMS: The Aquatic Life RO Buddie 4-Stage RO/DI water filter system for aquarium uses reverse osmosis to remove debris from tap water to give you clean water for your fish tanks, humidifiers, fountains, and more.
- WHAT THE SEDIMENT FILTER DOES: Water is filtered through a sediment filter in this reverse osmosis aquarium filter system that catches dirt like sand, silt, and more, which affects the quality and appearance of water.
- REMOVES CHLORINE AND ODORS: The carbon block filter in this water filter helps take out chlorine and unpleasant smells, so water is safer for fish and plants (Note: it wont remove chloramines).
- THE RO MEMBRANE FILTER: The RO membrane filter in this RO water filtration system for aquariums filters almost everything else, removing most total dissolved solids, turning tap water into much cleaner water which is gentler for sensitive aquatic life.
- FINAL POLISH: After the RO membrane, water passes through a color-changing deionizing resin in this RO/DI reverse osmosis system to remove the remaining TDS, and changes color from blue to tan so you can see when it needs replacing; If you want full performance specs, download the products technical PDF for info
Brand: Aquatic Life
Special Feature: Compact, Portable
Product Dimensions: 13.75"L x 7.5"W x 6"H
Material: Sediment, Carbon, RO Membrane, DI Resin
Capacity: 50 Gallons
Included Components: RO Buddie Four Stage Reverse Osmosis System Cartridge
Package Information: Cartridges
Installation Type: Wall Mount
Purification Method: Reverse Osmosis & Deionization
Power Source: Not an Electric Unit
Is Discontinued By Manufacturer : No
Product Dimensions : 14 x 4 x 7.5 inches; 3.9 Pounds
Item model number : 540019
Department : all ages, unisex
Date First Available : August 19, 2004
Manufacturer : Lifetime Products LLC
Best Sellers Rank: #8,736 in Pet Supplies (See Top 100 in Pet Supplies) #25 in Aquarium Filters
#25 in Aquarium Filters:
Customer Reviews: 4.5 4.5 out of 5 stars (5,016)
Other Special Features of the Product: Compact, Portable
Container Type: Cartridges
Installation Type: Wall Mount
Purification Method: Reverse Osmosis & Deionization
Power Source: Not an Electric Unit
Maximum Flow Rate: 180 Liters Per Day
Upper Temperature Rating: 100 Degrees Fahrenheit
Supported Water TDS Level Maximum (PPM): 500
Smart Home Compatibility: Not Smart Home Compatible
Item Dimensions L x W x H: 13.75"L x 7.5"W x 6"H
Capacity: 50 Gallons
Item Weight: 3.9 Pounds
Material Type: Sediment, Carbon, RO Membrane, DI Resin
Brand Name: Aquatic Life
Included Components: RO Buddie Four Stage Reverse Osmosis System Cartridge
Model Name: 540019
Model Number: 540019
Warranty Description: 1-Year Limited
UPC: 810957010195
Global Trade Identification Number: 95
Manufacturer: Lifetime Products LLC
Part Number: 540019
Item Type Name: Aquatic Life RO Buddie Four Stage Reverse Osmosis System
Unit Count: 1 Count
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Friday, Jun 26
Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Top Amazon Reviews
Size: 50-Gallon Four stage
I purchased the RO Buddie 4-stage RO/DI 50 GPD filter. This is for my small freshwater setup which includes seven tanks of varying volumes with a total volume of just under 100 gallons. I went with the RODI and not just RO system because I am trying to decrease the alkalinity of my water. So far so good after filtering 10 gallons of RO/DI water. It's very easy to set up and my water parameters have come out excellent with zero PPM TDS and zero EC (see attached photos, the meter was calibrated today). I live in Coastal Georgia and have moderately soft water parameters from the tap at around 150 PPM TDS (total dissolved solids) with a significant amount of EC (electrical conductivity) due to the high amount of minerals in the water. So basically very low sediment but high mineralization and somewhat moderate GH and KH. I have had a hard time keeping my South American tanks at good parameters for my tetras to breed and this will help immensely if it continues to work as it has so far. A Few Tips: - tighten the deionization filter cap before you install, I had a small leak as mine was somewhat loose but that was easy to fix and find and I just tightened the cap of the actual filter body itself and the leak stopped. To do it correctly I took all the hoses out and tightened it that way so I would not torque the hose connections. - this can be run off of any hose or even many kitchen and bathroom sink setups if you take out the aerator from your faucet. I am personally running it off of my laundry room and it's running beautifully as there is both a supply of cold water and a drain for the wastewater. - if you're going to install it in your laundry room all you need is a t-joint hose splitter or some other sort of double hose splitter that fits the receptacle for your washing machines supply water and gray water drain (see attached photos of my setup, everyone's will vary and I had to measure mine specifically as there are a huge variety of hose splitters) - if you are are doing a laundry room setup like mine where you can mount it close to the washing machine then the amount of hose provided in the kit will be more than sufficient. However if you are doing some other sort of setup you may want to buy additional hose, as you will need not just the proper amount of hose for the treated water but also the appropriate length of hose for wastewater. You could of course use a bucket but if you want to appropriately drain it to a sink or drain, getting additional hose maybe necessary. - if you are using this for a freshwater setup like I am you must absolutely get an additive that will keep the GH and KH at appropriate levels. RODI water by itself will kill fish. - Read the darn instructions. For a cheap system like this they are actually fairly detailed and obviously written by somebody who speaks English fluently. - having a solid set of channel locks or a wrench that will fit into a small area, as well as Teflon tape for the female ends of the threaded connections, will help reduce the potential for leaks. I am on city water that withdraws from a river and and underground aquifer and it is at a fairly high PSI as I live only 2 mi from the treatment center. All in all I am really pleased so far as this is the least expensive system I could find. This would not be an appropriate system for drinking water as the pressure/supply would not be great enough to fill a glass in a reasonable amount of time. Right now I am averaging about 5 gallons of treated water every 90 minutes (around 80 GPD) which is far above the 50 gallons per day that the system rated for, although I expect that to eventually go down as the sediment and carbon filters begin to fill with debris. That said, I am currently probably experiencing closer to a 75 GPD or even 100 GPD system which got $70 is impossible to beat. As an added bonus when the RO finally wears out I can replace it with one of their 75 GPD or 100 GPD rated filters so long as I swap out the The 450cc flow restrictor for an 800cc flow restrictor, thus functionally increasing the output of the system. This will of course wear out the DI filter faster. I will update this review if anything changes but so far I am pleased. For some reason Amazon's AI wants me to comment on the noise level which is silly for a system of this low of a flow rate. If it's making any noise louder than a few gurgles and bubbling sounds that you can only hear when you are right next to it then there is probably something wrong with the system like over pressure or an incorrectly installed hose connection which is creating suction and/or air intrusion somewhere. So, tldr, it doesn't make any noise. In summary, it's a cheap effective system that took me about 20 minutes to install with just the parts in the box and the hose splitter I bought. Hard to go wrong at this price point. I would recommend this to anyone who needs a small amount of water for weekly or bi-weekly water changes and is trying to keep the GH and KH of the water column down (i.e. slightly acidic or neutral). note: The picture system has not been fastened to my wall yet nor have I done any hose management so bear that in mind as well.
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Reviewed in the United States on October 25, 2025 Reviewed in the United States on October 25, 2025 by Diego Marzipan
Size: 50-Gallon Four stage
Very happy with this product. I got the DI package for my carnivorous plants, but also wanted to use it for drinking water (we are on a small tribal water system where quality is sometimes unreliable and the nearest town where you can buy RO in is a former superfund site). We used a 1/4" Y fitting to split the water after the RO membrane with 1 tube going to a ball valve and then the DI unit and the other side going to another ball valve and then the Watts PH Balancing & re-mineralizing Filter. The ball valves here may be overkill, but I didn't want to risk any back-flow into the DI unit. We used some blue 1/4" tubing so we would know which one was the drinking water tube. We used about 6 feet of tubing after both the DI and Watts filter and then another ball valve and another 20 or so inches of tubing, so the tubing stays in place in 5 gallon bottles and the flow can be turned off right at the bottle. You could one ball valve on each side. We tried drinking the RO without the Watts filter because I couldn't imagine it being as bad as people claimed. But it was. RO changes the Ph to acid (?) and lack of minerals leaves it flat. My husband said he thought it tasted like a bird had pooped in his mouth. I said it was more like bat guano. Neither of us asked how the other knew what bird or bat feces tasted like. I think that's why our marriage has endured so many decades. People need secrets. Anyway, if you're hesitating on getting the Watts Ph and re-mineralizing filter, do yourself a favor and buy it. It is providing the best tasting water I have ever drank. Except for the water we got from the spring on our property we knew had arsenic in it from a former gold mine. That stuff was delicious. Unhealthy, but fantastic tasting. In case you miss it, the pamphlet directions say to let the water run through the filter for 30 minutes before hooking up the RO membrane cartridge. However, the label on the filter says to run it 1 hour before hooking up the RO membrane. Run it an hour. This is definitely an important step. We have ours set up outside by our outdoor shower. It gets morning sun. After about 2 weeks, the resin in the DI cartridge had fully changed color, despite having only run about a half gallon of water through it. We do have a fair bit of rust sometimes and I thought perhaps it was that. I pulled out my TDS meter today because carnivorous plants ain't cheap to replace. Although it looked like it was exhausted and fully color changed, the TDS meter still showed 0.00. I then double-checked the TDS meter was working properly with several other levels of filtered water. So, even if your DI resin looks as though it has changed color completely you'll want to see what the actual TDS output is. In the future I'd either cover my DI cartridge or keep it out of the sun. Lastly, we have terribly low water pressure. Our water comes from a ground well, then is pumped up a hill a few feet into a storage tank, then is gravity fed to houses. I thought the water was partially turned off the first time I turned a tap on here, it's that low pressure. I'm not sure exactly what it is, pressure-wise, but I've never seen such low pressure outside of spring-fed systems without any storage tank. Anyway, we still get about 2 gallons per hour out of this RO unit. Our water starts out generally at around 90 ppm, so not too much to remove and maybe that's why it still gives decent output at such low pressure, idk. Just thought I'd mention it because our low water pressure was one thing that caused me to hesitate in buying an RO unit so long. This is so much more convenient (and reliable) than dragging home bottles of distilled water for carnivorous plants and refilling bottles for drinking water at the market. In sum, this item is a great deal and I would recommend it for drinking and DI water uses.
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Reviewed in the United States on June 20, 2018 by Ess
Size: 50-Gallon Four stage
So this is my honest opinion about this RO filter system now I got the 50 gallon because I have a 60 gallon cube so I’m gonna give you the pros and cons and how easy is it to set up or not set up we’ll start with the pros pretty compact pretty easy well not pretty easy to set up. I’ll leave that for later. Another pro is that this product for $70 it’s worth the price another pro it seems pretty fast I mean in like the next hour you got a half a gallon and then the next couple minutes you get a full gallon now let’s start with the cons building this product. I figured out that this product was not the best to build. It seemed like the instructions were not very accurate, but that was on my hand. Another thing is that the faucet adapter wasn’t really the best I mean, don’t get me wrong. It’s good and whatever it is but definitely could rather there’s still some leakage that comes out even when you tight it so I have a problem with that, but that’s probably just on my hands with leakage. It’s a mixed opinion. That’s another con with me. It’s a mixed opinion about the leakage because when I first built it, it was leaking like crazy but the second time I rebuild it it wasn’t leaking so definitely make sure you’re having the cleanest cuts with the razor blade into tubing. Another thing is is that you another con is that you have to push your tubing really deep into the filter culture thing so then you don’t have other leaks. Another con is definitely they’re gonna still have guaranteed with the faucet adapter and then for easy to build, I would just say it’s all right for building, but it’s not expertise building either because again you have to get the cleanest cuts and then you have to focus on what to do. It’s not really my mojo. Don’t get me wrong, but building overall was kind of annoying. It was like you know the system itself is fine but building it is just not for what I wanted to deal with but definitely I had to rebuild mines but you know everybody’s filter system that they got from the 50 gallon is all different so I’m not the one to judge the filter but it’s pretty good overall
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Reviewed in the United States on February 19, 2026 by V
Size: 50-Gallon Four stage
The product is a easy setup and works, the only con for me is that the male/female adapter that screws where the aerator sits is made out of cheap plastic and broke easily on testing the product. Since it was working before trying to remove and breaking i went to buy another.. the only problem with that is they don't sell the cheap plastic piece they sell a metal adapter. Why wouldn't you charge the extra 10 bucks and send your customers the better quality parts so we don't have to worry about getting the m/f adapter out of the faucet? other than that this product is as advertised, a great cost effective RO system for small aquariums and in my case small time growers.
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Reviewed in the United States on August 14, 2025 Reviewed in the United States on August 14, 2025 by Bobby Johnson
Size: 50-Gallon Four stage
Size & Setup: The Aquatic Life RO Buddie 4-stage RO/DI unit is compact and easy to set up, making it ideal for smaller spaces or hobbyists who don’t need a large permanent system. Performance & Water Quality: Despite its size, it’s very effective, producing clean, high-quality RO/DI water suitable for aquariums and other uses. Maintenance Considerations: Because of the smaller filters, you’ll need to change the cartridges more frequently, depending on your incoming water quality and total gallons processed. Final Verdict: If you want a small, effective RO/DI system, this unit does the job well. Just be aware of the more frequent filter changes due to its compact design.
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Reviewed in the United States on January 2, 2026 by marco Agliano
Size: 50-Gallon Four stage
This review is for the RO/DI. After following instructions to set up, the result for filtered water was 0 TDS using the HM Digital COM-80 meter. That’s ideal for remineralizing water before using in our aquariums. Please note, the filter can be damaged if your local water has chloramines- a mixture of chlorine and ammonia used to disinfect water. Our local water only has chlorine but I did not know to check before purchasing. Also, *wait to connect the DI filter* until after the step in the instructions to drain all preservative from the RO filter by running it for 30 minutes.
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Reviewed in the United States on May 23, 2026 Reviewed in the United States on May 23, 2026 by supercerealsteph
Size: 50-Gallon Four stage
Nice complete system, very straight forward to set up, as long as you read the instructions first. the system works great.
Reviewed in the United States on April 7, 2026 by Chico
Size: 50-Gallon Four stage
Wow! Who needs to pay $250 for an RODI filter?! This is my first time with a reef tank since RODI became the norm, so I don't have experience with other filters. I know the more expensive ones come with their blow and whistles, but we have pretty good pressure at the house, so I figured we wouldn't need measuring gages. And I have a separate TDS pen meter, so no need for that in the unit either. I kept scratching my head over the ~$200 units when I saw this one and decided to give it a try. For ~$60 it's been great so far. I installed under my sink very easily, just purchased a T valve with this adapter (link below). So far have it's given me maybe 150Gal of crystal clear filtered 0000ppm water (our municipal source water is around 0040ppm out of the tap). It takes 2-4 hours I estimate to fill a 5Gal bucket and I don't need that much water for my 53Gal system. Doesn't remove chloramines and with strip testing we seem to have just a tiny bit of undetectable chloramines in the water in and out of the filter (or maybe not... the strips are hard to reach and almost looks like zero). So just in case I dose some Dr Tim's First Defense as per the instructions, before using and that seems to take care of it without a problem. Now, caveat emptor: my tanks are still cycling, so we don't have any livestock in them that can proof we've put this filter through the ultimate test, but 0000ppm is good enough for me and my nitrifying bacteria seem to be thriving in this water after two weeks cycling almost complete (chart attached). So that's a good sign for me. Haven't had to deal with replacing cartridges, so I can't attest either on availability, price etc. But I'll update if anything happens. Customer service was great too. I had questions as my resin cartridge looked wet and the color change that tells you is worn out was hard for me to say. So I wrote to their customer service address in the manual and they replied quickly and explained to me how to read the colors and that it does need to be moist in shipping, so we're good. I know RODIs pay for themselves in the equivalent of a few trips for water to the LFS, but this one paid for itself before the first trip!
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Reviewed in the United States on March 21, 2022 Reviewed in the United States on March 21, 2022 by E