10 Best Cold Plunge Chillers for Stock Tanks (June 2026) Complete Guide

Building a cold plunge with a stock tank is one of the smartest DIY investments you can make for recovery, but without a reliable chiller, you are stuck buying bags of ice every single day. I have spent months researching and comparing the best cold plunge chillers for stock tanks, testing different HP ratings, plumbing setups, and filter systems to find out which units actually hold up over time.

Stock tanks make incredible cold plunge vessels. A standard 100-gallon Rubbermaid or galvanized tank gives you plenty of room to submerge, and they are built tough enough to handle years of outdoor exposure. The missing piece is almost always the cooling system. That is exactly what this guide covers: which chillers work best with stock tanks, how to size them for your setup, and what real users report after months of daily use.

Our team looked at 10 chillers across every price range and horsepower category. Whether you are cooling a 50-gallon tank in a mild climate or a 150-gallon setup in the Texas summer heat, there is a unit on this list that will fit your situation. I will walk you through each one with honest feedback from actual owners, not marketing fluff.

Top 3 Cold Plunge Chillers for Stock Tanks

Best Cold Plunge Chillers for Stock Tanks in 2026

1. PlungeFit 1HP Ice Bath Water Chiller – Most Powerful for Large Stock Tanks

If you are running a large stock tank, say 100 to 150 gallons or more, the PlungeFit 1HP is the unit that will actually keep up. Most 1/3 HP chillers struggle once you push past 80 gallons, especially in warm weather. This one handles up to 230 gallons without breaking a sweat. I have seen users report getting their 150-gallon outdoor tub from room temperature down to 39 degrees Fahrenheit in about 3 hours, which is remarkably fast.

The build quality stands out immediately. At 73 pounds, this is a substantial piece of equipment, not a flimsy plastic shell. The caster wheels are a small but meaningful detail. If you need to move your chiller between an indoor and outdoor setup, or just reposition it for maintenance, those wheels save you from having to dead-lift 73 pounds of metal.

The LED controller gives you precise temperature management with auto on/off cycling. Once you set your target temperature, the compressor kicks in and out as needed to maintain it within a tight range. Users consistently praise how stable the temperature stays, even through overnight periods when ambient temperatures shift.

The external filter pump system uses a 5-inch 20-micron filter that does a solid job keeping debris out of the cooling loop. For stock tank owners who use their setups outdoors where leaves, grass, and dust can contaminate the water, having effective filtration directly integrated into the chiller system makes maintenance much more manageable.

Who Should Buy This Chiller

This is the right pick if you have a large stock tank (100 gallons or more) or live in a hot climate where a smaller chiller would run constantly trying to keep up. It is also ideal for anyone running their cold plunge outdoors year-round. The 1 HP compressor gives you headroom that smaller units simply cannot match.

People who want to cool down quickly between sessions will also benefit. Instead of waiting overnight for temperatures to recover after a plunge, this unit can pull the water back down in a few hours.

What to Watch Out For

The main concern is the limited track record. With only 16 reviews, this is a relatively new product. One user reported receiving a defective unit with a leaking issue and struggled to reach customer support for a return. That said, 92 percent of reviews are 5-star, and the users who got working units are extremely happy with performance.

At 73 pounds, make sure you have a sturdy surface to place it on. It also draws 2500 watts, so check that your circuit can handle the load, especially if you are running other equipment on the same line.

2. The Pod Company Pro Water Chiller 0.5 HP – Best for Hot Climates

The Pod Company Pro is specifically engineered for people dealing with high ambient temperatures. If you live somewhere that regularly hits 90 degrees Fahrenheit or more, this 0.5 HP unit was built with your situation in mind. It is optimized to perform even when the surrounding air temperature is above 85 degrees, which is exactly where most 1/3 HP chillers start to struggle.

Setup is genuinely quick. Multiple users report going from unboxing to running in about 5 minutes. The system uses a straightforward connection with their Ice Pod and Long Pod products, but it works with stock tanks too. You just need to adapt the hose connections to your tank’s plumbing, which is a simple hardware store trip.

The 24/7 water circulation is a feature I really like. Instead of cycling the compressor on and off, the water keeps moving continuously through the 20-micron filtration system. This means cleaner water and more consistent temperatures throughout your entire tank. No cold spots, no stagnant sections.

Cooling down to 39 degrees Fahrenheit is impressive for a portable unit. That is cold enough for serious cold therapy. Users in Arizona, Texas, and Florida report maintaining temperatures in the low-to-mid 40s even during peak summer, which is exactly what you need from a chiller marketed for hot climates.

Who Should Buy This Chiller

Choose this one if you live in a hot climate and your stock tank sits outdoors or in a warm garage. The 0.5 HP compressor gives you more cooling power than a 1/3 HP without the power draw of a full 1 HP unit. It hits a nice middle ground for serious users who need reliable performance in tough conditions.

It is also a strong option if you value fast setup and want something that works out of the box with minimal plumbing modifications.

What to Watch Out For

The most common complaint involves plastic seals and fittings leaking. Several users have reported that the faucet seals break over time, causing slow leaks. Upgrading to brass fittings at the connection points is a common fix that experienced cold plunge owners recommend. There are also recurring complaints about customer support being slow or unresponsive when issues arise.

At 10 pounds, the listed weight seems too low and may be a listing error. Expect a heavier unit in reality. Also, some users needed to bleed air from the filter port before the system would circulate properly.

3. 1stplunge 1/3HP Cold Plunge Chiller with Built-in Pump – Best Build Quality

A perfect 5.0 rating across 12 reviews is rare in the cold plunge chiller market. The 1stplunge 1/3HP with built-in pump has managed to impress every single buyer so far. The standout feature here is the built-in pump and metal filter combination, which means you never need to buy replacement filter cartridges. That saves money and hassle over time.

I like that this unit includes upgraded insulated hoses right out of the box. One of the most common complaints across all chiller brands is heat gain through the connection hoses. When your hoses are not insulated, the water warms up between the chiller and the tank, making the compressor work harder. The insulated hoses on this unit help keep the cold where it belongs.

Users consistently mention the 10-minute setup time. The plug-and-play design means you connect the hoses, drop the submersible pump in your stock tank, plug it in, and set your temperature on the LED touchscreen. No special tools, no plumbing modifications, no trips to the hardware store for adapters.

The quiet operation gets mentioned in almost every review. At 600 watts, this chiller runs efficiently and does not produce the loud buzzing that some competing units are known for. If your stock tank is near your bedroom or living space, this is one of the better options for keeping noise to a minimum.

Who Should Buy This Chiller

This is an excellent choice for someone who wants a hassle-free, low-maintenance setup. The built-in metal filter that never needs replacing is a genuine advantage over units that require regular filter cartridge purchases. It is ideal for stock tanks up to about 80 gallons in moderate climates.

If you are new to cold plunges and want something that works perfectly from day one without tinkering, this is one of the safest bets on the market right now.

What to Watch Out For

The main consideration is that 12 reviews, while all perfect, is a small sample size. There is always some risk with newer products that have fewer long-term durability reports. The 1-year warranty helps mitigate this, but keep an eye on the warranty terms.

At 79 gallons of rated capacity, this unit is best for standard stock tanks. If you are running a larger 150-gallon tank, you may want to step up to a higher HP option from this list.

4. AS ColdPlunge 1/3 HP with Built-in Filter and Pump – Best Customer Support

Customer support matters more than most people realize when buying a cold plunge chiller. Things go wrong with these units, and having a responsive manufacturer makes the difference between a quick fix and weeks of frustration. The AS ColdPlunge model AS-AY300 consistently gets praised for responding to issues within 24 hours with detailed, helpful answers.

The built-in metal filter is a feature I wish more manufacturers would adopt. Instead of buying replacement cartridges every few weeks, you simply remove the metal filter, rinse it clean, and put it back. Over the course of a year, that saves you a significant amount of money and eliminates one more thing to remember to order.

This unit ships with insulated hoses and a submersible pump, giving you everything needed to connect it to a stock tank. Users report successfully running it with tubs well beyond the rated 79-gallon capacity. One reviewer mentioned using it with an oversized 120-gallon setup and achieving consistent temperatures in the mid-40s range.

The upgraded insulated hoses do a good job preventing heat gain during circulation. The LED touchscreen makes temperature adjustments straightforward. You set your target temperature and the compressor maintains it automatically. Several reviewers mention specific health benefits they have experienced, including reduced inflammation and improved sleep quality.

Who Should Buy This Chiller

Choose this model if reliable customer support is a top priority for you. It is also a strong pick if you want a low-maintenance filtration system that does not require ongoing purchases. The combination of built-in filter, insulated hoses, and a submersible pump makes it a complete package that is ready to connect to your stock tank right out of the box.

People running slightly larger tubs than the rated 79 gallons will also find this unit capable of handling the extra volume, based on real user reports.

What to Watch Out For

The temperature display tends to read about 3 degrees warmer than the actual water temperature. This is a known issue across several chiller brands, but it is worth being aware of so you can adjust your settings accordingly. Some users recommend using a separate thermometer to verify the actual water temperature.

The unit can be loud when the compressor is running. If your stock tank setup is near living spaces or bedrooms, this could be an issue. The floating intake tubes are another common complaint. You may need to attach small weights to keep them submerged properly.

5. 1stplunge Ice Bath Chiller and Tub Kit 1/3 HP – Best All-in-One Starter Kit

If you are starting from zero and do not already have a stock tank, this kit from 1stplunge gives you everything in one box. You get the 1/3 HP chiller unit plus a 148-gallon oval tub with 7-layer reinforced PVC construction. It is designed for people who want to skip the DIY plumbing phase and get plunging quickly.

The tub uses Oxford fabric with thick EPE insulation, which helps maintain water temperature between sessions. The chiller connects directly to the included tub through quick-connect adapters, so there is no guesswork about fittings. The external 20-micron filter keeps the water clean, and the smart touchscreen controller lets you dial in your target temperature.

Setup takes about 15 minutes according to multiple reviewers. The included accessories are generous: submersible pump, three hoses, quick-connect adapters, a tote bag for storage, a dust cover, and an insulation cover. For someone who does not want to research and source individual components, this bundle saves considerable time.

The chiller maintains temperatures around 48 degrees Fahrenheit reliably, though getting down to the advertised 42 degrees may take patience in warmer conditions. Customer service gets high marks across reviews, with the company responding quickly to issues and sending replacement parts when needed.

Who Should Buy This Chiller

This kit is perfect for beginners who want a complete all-in-one solution. If you do not already own a stock tank and do not want to hunt for compatible plumbing fittings, this bundle eliminates those decisions entirely. It is also a good option for anyone who wants a portable setup they can take down and store when not in use.

The included dust cover and tote bag make this a practical choice for people with limited space who need to pack up their cold plunge between sessions.

What to Watch Out For

Tub quality is inconsistent. Several users reported receiving units with holes in the lining or minor leaks at the seams. The company appears to be responsive about sending replacements, but it is an inconvenience. If you buy this kit, test the tub with water before setting up the chiller to catch any leaks early.

The PVC tub, while insulated, is not as durable as a metal or rigid plastic stock tank. If you plan to leave your setup outdoors permanently, a galvanized or Rubbermaid stock tank paired with a separate chiller will hold up better over the years.

6. AS ColdPlunge 1/3 HP with External Filter – Budget-Friendly Daily Driver

The AS ColdPlunge model AS-DY300 is one of the more affordable 1/3 HP options on the market, and it has been around long enough to accumulate nearly 200 reviews. That gives us a much clearer picture of long-term performance than newer competitors with single-digit review counts.

Users in Texas and other hot climates report that this chiller keeps their stock tank water in the 46 to 48 degrees Fahrenheit range even through summer. That is not as cold as some higher-powered units can achieve, but it is cold enough for effective cold therapy. The external pump and 20-micron filtration system work together to keep water circulating and clean.

At 31 pounds, this is one of the lighter chillers in its class. That makes it easier to position and move if needed. The LED touchscreen control panel is responsive, and the 600-watt compressor is reasonably energy efficient for daily operation.

The main thing to know is that initial cool-down takes time. For a full 79-gallon stock tank starting at room temperature, expect to wait 2 to 3 days before reaching your target temperature. Once the water is cold, the chiller does a good job maintaining it. But the initial pull-down is slow compared to higher HP units.

Who Should Buy This Chiller

This is a sensible choice for budget-conscious buyers who want a proven 1/3 HP chiller with a decent track record. If you have a standard 70 to 80 gallon stock tank and live in a moderate climate, this unit will handle your needs without overpaying for capacity you do not use.

It is also worth considering if you already have a separate filtration setup and just need a reliable cooling unit.

What to Watch Out For

The plastic fittings are the most common failure point. Multiple reviewers recommend upgrading to brass fittings immediately to prevent leaks. The filter can also restrict airflow if not replaced regularly, which causes the pump to overwork. Keep spare filters on hand.

There is no automatic shut-off at the desired temperature, so you need to monitor the unit or set up a separate timer. The temperature display accuracy is off by about 3 degrees, so verify with an independent thermometer.

7. PlungeFy 1/3 HP Ice Bath Water Chiller – Best Filtration System

The PlungeFy chiller stands out for having a 1-micron filtration system, which is significantly finer than the 20-micron filters found on most competing chillers. For stock tank owners dealing with outdoor debris, algae concerns, or just wanting the cleanest possible water, this is the best filtration you will find at this price point.

The stainless steel construction is another differentiator. Most chillers in this range use basic painted metal or plastic housings. Stainless steel resists corrosion better, which matters if your chiller lives outside near a stock tank that gets splashed during use.

This unit ships as a complete pro kit: submersible pump with suction cups, upgraded insulated hoses, waterproof tape, and an intelligent HD touchscreen panel. The universal compatibility means it works with cold plunge tubs, home bathtubs, and stock tanks without needing special adapters.

With 64 reviews, the PlungeFy has a decent sample size for evaluation. The split is interesting: 61 percent are 5-star and 26 percent are 1-star. The happy users praise the fast cooling, quiet operation, and clean water. The unhappy users mostly report pump failures after several months and difficulty reaching the seller for replacements.

Who Should Buy This Chiller

Choose the PlungeFy if water cleanliness is your top priority. The 1-micron filter provides noticeably cleaner water than standard 20-micron systems, which makes a real difference if you are plunging daily and want to minimize chemical treatments.

It is also a good fit if you have an unconventional tank setup. The universal compatibility and included adapters mean it will connect to almost anything without extra shopping trips.

What to Watch Out For

Durability is the concern here. About a quarter of reviews report some form of failure, typically pump issues after a few months of regular use. On the positive side, customer service has been good about sending replacement units to affected buyers. Just be prepared for a possible exchange during your first year.

The rubber silicone gasket must be properly seated during assembly, and plumber’s tape is needed for a proper seal. Rush through setup and you will be dealing with leaks. Take your time with the connections.

8. Ezcasch 1/3 HP Aquarium Chiller – Best Budget Option for Small Stock Tanks

The Ezcasch chiller is technically an aquarium chiller, but the cold plunge community has been using aquarium chillers for years with good results. At its price point, it is one of the most affordable ways to get into automated cold water cooling for your stock tank. It is Prime eligible too, which means fast shipping and easy returns if something is wrong.

The dual built-in fans and large heat dissipation vents do a solid job of moving heat away from the compressor. For a 50 to 70 gallon stock tank in a mild or moderate climate, this unit has enough cooling capacity to maintain therapeutic temperatures. The noise level stays under 40 decibels, which is roughly the volume of a quiet conversation.

Being an aquarium chiller means you will need to handle the plumbing adaptation yourself. The included fittings are designed for fish tank tubing, not the larger diameter hoses common on stock tank setups. A quick trip to the hardware store for PVC adapters and hose clamps will solve this, but it is an extra step.

Users report that the chiller works well once properly set up and connected. The English manual includes troubleshooting guidance, which is helpful since the setup is not as straightforward as purpose-built cold plunge chillers. For mechanically inclined users, the adaptation is straightforward.

Who Should Buy This Chiller

This is the right pick if you are on a tight budget and have a smaller stock tank (under 70 gallons). It is also a good choice if you are handy with basic plumbing and do not mind adapting the connections yourself. The savings compared to purpose-built cold plunge chillers are significant.

People who already have an external pump and filtration system will find this chiller easy to integrate, since you can use your existing water circulation setup.

What to Watch Out For

Long-term durability is a question mark. Some users report failures after about 4 months of continuous use. The chiller is designed for aquarium use where the temperature differential is typically smaller, so pushing it to maintain 40-something degree water in a stock tank is working it harder than intended.

You will need to source additional parts for the plumbing connection to your stock tank. Factor that extra cost and time into your decision. The temperature display may also need calibration to reflect actual water temperature accurately.

9. Fox Plunge 1/3 HP Cold Plunge Chiller – Best Remote Control Option

The Fox Plunge chiller is the only unit on this list that ships with a remote control, and that is a more useful feature than it might sound. When your stock tank and chiller are set up outside, being able to adjust the temperature or check settings without walking over to the unit and crouching down to read the display is genuinely convenient.

The 3-micron filtration system is finer than the 20-micron standard on most competing units. It sits between the PlungeFy’s 1-micron system and the standard 20-micron offerings, giving you good water cleanliness without the replacement cost of the finest filters. The activated carbon and ultra-filtration combination handles both particles and odors.

This chiller ships as a complete kit. The included components cover every connection scenario: chiller unit, external filter and pump, submersible pump, hose connectors in both 20mm and 25mm sizes, three insulated cotton hoses, remote control, screws, screwdriver, tape, power cord, and an installation manual. You will not need to buy anything extra for a basic stock tank hookup.

The LED display is clear and the interface is intuitive. At around 35 pounds, it is manageable to position solo. The universal compatibility means it connects to stock tanks, inflatable tubs, and home bathtubs without issues.

Who Should Buy This Chiller

This is a practical choice for anyone who wants the convenience of remote control operation. If your chiller is positioned somewhere hard to reach or you simply prefer adjusting settings from a distance, the Fox Plunge is the only option that includes this feature standard.

It is also a solid mid-range pick for people who want a complete kit with above-average filtration. The 3-micron system is a meaningful upgrade from 20-micron competitors without going to the expense of a 1-micron setup.

What to Watch Out For

Cooling efficiency drops noticeably in extreme summer heat. If you live in a consistently hot climate and your stock tank is in direct sun, this unit may struggle to maintain temperatures below 50 degrees during peak afternoon hours. Shade your tank or consider a higher HP option for those conditions.

The filter cartridges require regular replacement, adding to the ongoing cost of ownership. The included pump and filter quality has received some criticism, so be prepared to potentially upgrade those components if you experience issues.

10. QAMGCYW 1/3 HP Ice Bath Water Chiller – Corrosion-Resistant Design

The QAMGCYW chiller uses a pure copper condenser paired with a titanium evaporator, which is a higher-end component combination than you typically find at this price point. Copper condensers transfer heat efficiently, and titanium evaporators resist corrosion from treated water. For stock tank owners who use hydrogen peroxide or other water treatments, this corrosion resistance matters.

The dual high-speed fans provide aggressive heat dissipation, and the unit claims 30 percent energy savings compared to similar chillers. While independent verification of that claim is difficult, the efficient component design suggests it should draw less power than basic models with standard condensers.

This chiller is rated for tanks up to 66 gallons, which makes it better suited for smaller stock tanks or a partially filled larger tank. If you have a standard 100-gallon stock tank filled to about 60 to 65 percent capacity, this unit is sized appropriately. Go beyond that and you will be pushing the compressor hard.

The extra-large LED display is easy to read from a standing position, which is a nice quality-of-life feature. The remote control adjustment adds convenience. The 2-year after-sales service with 24-hour response time is longer than the standard 1-year warranty offered by most competitors, giving you an extra year of coverage.

Who Should Buy This Chiller

Choose this chiller if you treat your stock tank water with chemicals and want components that will resist corrosion over time. The titanium evaporator is a real advantage for longevity in that scenario. The 2-year warranty is also the longest on this list, which provides extra peace of mind.

It is well suited for smaller setups: a 50 to 65 gallon tank, or a larger tank filled partially. People who want good energy efficiency and are willing to deal with some setup complexity will find value here.

What to Watch Out For

Setup is the main pain point. Multiple users report issues with leaks at the connection points and difficulty getting the pump primed. You may need to bleed air from the system before it will circulate properly, and the included instructions are not always clear on this process.

Some users found that the lowest achievable temperature was higher than the advertised 42 degrees Fahrenheit, hovering around 50 to 55 degrees in real-world conditions. One user received a unit with a leaking nozzle straight out of the box. With only 11 reviews, the sample size is small, so proceed with realistic expectations and test your unit thoroughly during the return window.

How to Choose the Right Cold Plunge Chiller for Your Stock Tank?

Picking the right chiller comes down to four things: your tank size, your climate, your budget, and how much maintenance you are willing to do. I have broken down each factor based on what real stock tank cold plunge owners report working and what does not.

Matching Horsepower to Your Tank Size

This is the single most important decision you will make. Undersizing your chiller is the number one mistake new cold plunge builders make. Here is what I recommend based on user reports across forums and reviews:

A 1/3 HP chiller is the sweet spot for most stock tank setups. It handles 50 to 80 gallons effectively in moderate climates. If you live somewhere with mild summers and your tank is indoors or in the shade, a 1/3 HP unit will serve you well.

A 1/2 HP chiller is the right call for 80 to 120 gallon tanks or for anyone in a hot climate where summer temperatures regularly exceed 90 degrees. The extra cooling capacity prevents the compressor from running constantly.

A 1 HP chiller is what you need for tanks over 120 gallons or for setups in extreme heat. The PlungeFit 1HP on this list is rated for up to 230 gallons. If you have a large stock tank and want fast cool-down times, this is the way to go.

Climate Considerations

Your local climate affects chiller performance more than almost any other factor. A 1/3 HP chiller that works beautifully in a 70-degree garage will struggle to keep up in 100-degree Arizona sun. If your stock tank is outdoors, factor in direct sunlight exposure and ambient temperature ranges.

Forum users from Minnesota and other cold-weather states report that even small chillers work well during fall, winter, and spring. The challenge is summer. Users in Texas, Florida, and Arizona consistently recommend going one HP size larger than you think you need. The few extra dollars upfront saves you from a chiller that runs nonstop and still cannot hit your target temperature.

Built-in vs External Filtration

Some chillers come with built-in metal filters that you rinse and reuse. Others use external filter cartridges that need regular replacement. The built-in approach saves money over time but may not filter as finely. External cartridge systems, especially those with 1 to 3 micron ratings, produce cleaner water but require ongoing purchases.

For outdoor stock tanks where debris is a constant issue, a finer external filter system makes more sense. For indoor setups in controlled environments, a built-in filter is usually sufficient.

Plumbing and Installation Tips

Most stock tank cold plunge builders use 1/2-inch or 3/4-inch PVC or garden hose connections between the chiller and the tank. Here are the key tips that experienced users consistently recommend:

First, upgrade to brass fittings wherever possible. The plastic fittings that come with most chillers are the most common leak point. A few dollars at the hardware store for brass adapters saves you from slow leaks that drain your tank overnight.

Second, use plumber’s tape on every threaded connection. It takes an extra 30 seconds per fitting and prevents the majority of leak complaints.

Third, position your chiller above the waterline if possible. This prevents backflow issues and makes it easier to bleed air from the system during initial setup.

Fourth, insulate your hoses. Even if your chiller comes with insulated hoses, adding foam pipe insulation from the hardware store further reduces heat gain between the chiller and your tank.

Maintenance for Longevity

Cold plunge chillers are an investment, and proper maintenance makes a real difference in how long they last. Based on forum discussions with owners who have run their units for multiple years:

Clean or replace your filter regularly. A clogged filter makes the pump work harder and reduces cooling efficiency. For built-in metal filters, a weekly rinse is usually sufficient. For cartridge filters, follow the manufacturer’s replacement schedule.

Keep the chiller’s air vents clear. Dust, leaves, and debris can block the heat dissipation vents, causing the compressor to overheat. A monthly wipe-down of the exterior vents takes two minutes and extends the life of the unit.

In freezing climates, drain the system before the first hard freeze if your setup is outdoors. Water left in the chiller can freeze and crack internal components. This is one of the most common causes of chiller death in northern states.

Frequently Asked Questions About Cold Plunge Chillers

Final Thoughts on Cold Plunge Chillers for Stock Tanks

Finding the best cold plunge chillers for stock tanks means matching horsepower to your tank size and climate. For most people with a standard 100-gallon stock tank in a moderate climate, the 1stplunge 1/3HP with built-in pump or the AS ColdPlunge 1/3HP with built-in filter give you everything you need at a reasonable price. If you are running a large tank or live in extreme heat, the PlungeFit 1HP handles that demand without breaking a sweat.

The cold plunge community has been building stock tank setups for years now, and the technology keeps getting better. Whether you are a first-time builder or upgrading from an ice-and-cooler system, any chiller on this list will save you time, money, and trips to the store for bags of ice. Pick the one that matches your tank, trust the user reviews, and start plunging.