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Here at Reef Tank Resource, we would be remiss if we didn’t cover the saltwater aquarium with fish only and live rock – no corals. Heresy you say? That’s no reef tank! Well, not so fast there buckaroo. Live rock is typically made up of coral, just not live coral. Semantics you say? Okay, fair enough. But reef tanks typically start out as FOWLR (Fish Only With Live Rock) prior to adding live corals. Also, a FOWLR saltwater aquarium is a great place to start as a beginner. Additionally, it’s great for advanced reefer too. What’s nice about a FOWLR is you can keep fish that normally wouldn’t work with a reef tank. Not to mention, a rock scape can be quite attractive in and of itself. This article will be all about a rock solid FOWLR tank setup for beginners. Let’s dive in.

Saltwater Aquarium Beginner Setup and Tips

Minimum 40 Gallon Tank

The more water volume the more stable your aquarium. Your fish will thank you. Don’t be tempted by those beautiful nano aquariums just yet. They are cheaper to set up but require a lot more attention and will cost you more in the long run.

Live Rock IS Your Filter

Common wisdom is to add 1 to 2 pounds of live rock per gallon but that doesn’t account for how porous your live rock is or how many fish you plan to keep. We could dive deep into live rock alone but that’s not what this article is about. If you want to dive deeper you can read all about it in our article Live Rock & Dead Rock – Aquascaping, Coralline Algae, & How Much. We recommend aqua-cultured live rock which you can supplement with some dead rock. After some time, the micro-organisms from your aqua-cultured rock spread to your dead rock. Pukani or Fiji is great because it is very porous which means it’s able to contain more micro-organisms.

Saltwater Aquarium Flow

You need a good amount of water flowing in, around, and through your rocks to allow the micro-organisms to break down the waste in the tank. A couple power heads are great and giving you the flow you’ll need. You don’t want to blow your fish around but a good current is a good thing.

Additional Saltwater Aquarium filtration

Hang on Filters

Generally, these aren’t very effective since they can’t hold too much media. If you have one already it wouldn’t hurt to add on though.

Canister Filters

Canisters are useful because they hold a lot more media but require frequent cleaning. Many find canisters more trouble than they’re worth.

Media Reactors

Very similar to canisters but much more effective. Reactors are not designed to capture particulates but simply run water through a media like Carbon. They don’t require frequent cleaning, just regular media changes.

Protein Skimmers

Probably the most popular filtration solution for a saltwater aquarium. It bubbles water in a chamber and dissolved waste adheres to the bubbles and floats up to a collection cup. These can be purchased as hang on types or in-sump types. More on sumps later.

Macroalgae Refugiums

These primarily resolve algae problems in your tank. Phosphates from the process of fish waste breaking down are what algae feed on. A refugium contains an easily manageable macroalgae, such as chaetomorpha, that feeds on the phosphates instead of algae in your tank. Like protein skimmers, they can be had as hang on or sump versions.


While not a filter, strictly speaking, it does house filtration devices. A sump is a separate smaller aquarium that typically sits underneath your main tank hidden in the stand. Water flows down to the sump and typically interacts with several filtration methods before being pumped back up to the main display tank. A common path through a sump would include:

  • Overflow (which skims detritus from the water surface)
  • Filter Socks
  • Protein Skimmer
  • Refugium
  • Bio Media
  • Return Pump

Depending on your circumstances you may not want to attempt a sump. They are highly recommended but not required. If you do think a sump is something you want to include you’ll want to prepare for it before purchasing any items. For more on sumps check out our Reef Tank Plumbing Guide – Designs, Diagrams, Sump, Overflow, Return to see what’s involved.


Obviously lighting is not  as critical for a fish only with live rock setup but it’s not unimportant. Proper lighting is still required for coraline algae growth. Traditional old school metal halides would likely be over kill. Not to mention they are expensive to run. Fluorescents are a solid choice with T5 bulbs being the best option. LED units are great for the ability to tune the color to your personal preference and program ramp up and down cycles.

Aquarium Temperature 78-80 degrees

Next, You will need to source a good heater for your tank. 3 to 5 watts per gallon is a good rule of thumb here. Heaters are notorious for failing. Like with all equipment in reefing, having a backup is a good practice. One method for redundant heaters is to have 2 set to different temps. One as a primary duty heater and the other to kick in as a backup. This only helps in a situation when one fails in the off position though. This solution only helps if a heater fails in the off position. To protect for failures in the on position you really need a reef controller or similar device. This way you can use it’s digital thermostat to control your heaters. Also, good reef controllers can monitor power consumption too so you can monitor both aspects of your heater incase the thermometer for the controller fails. A cheap solution for controlling heaters is the INKBIRD ITC 308S.

Also, get a couple thermometers. At a minimum I’d suggest an easily readable glass in-tank and a good digital thermometer. Don’t rely on your heater settings to be accurate.


Many people purchase pre-mixed saltwater at their local fish store. This is certainly the simple approach and a reasonable way to go. Carrying jugs of water once a month can get tedious so many people consider a RO/DI filter to make their own fresh and saltwater. Use fresh water to account for evaporated water and saltwater for changing 10 – 20 percent of your display tanks’ water volume once per month.

Mix your saltwater to a specific gravity of between 1.021 to 1.026. For measuring specific gravity (aka salinity) you’ll need a refractometer or similar device. Refractometers can sometimes but a little difficult to read by tend to be accurate. There are also digital tools available to do the job like the Milwaukee Digital Salinity Refractometer. They aren’t cheap but a dream to use. The easiest to use and still budget-friendly device is a hydrometer. A hydrometer isn’t the most accurate device but it will do the job and get you within the right range.


As tempting as it may be to throw Nemo and Dory in there on day one you’ll need you cool your jets there slick. Give the tank a couple weeks to stabilize. You don’t want to wake up one morning to your prized fish swimming upside down. Start slow and with hardy fish. Many people start off with Damsel fish because of their hardiness. I recommend researching fish compatibility before making any purchase decision though. Damsel fish are quite territorial and may bully fish you add later down the line. Only buy a couple fish to start. Slow and steady wins the race, and keeps the fish alive. Check out our Reef Safe Fish – Top 10 Best Options. It’s about reef safe fish but the majority of the list includes hardy options.

Clean Up Crew

Finally, after your tank is established, purchase a good clean up crew. Read our The BEST Clean Up Crew Critters for a good overview. A good clean up crew breaks down detritus and helps keep the tank clean. Snails are the best option. Hermit crabs do a great job too. You can also purchase some shrimp which will liven up the aquarium as well. Personally I love clean up crews almost as much as the fish. I have an emerald crab that has loads of personality.

In Conclusion

WHEW! There is a lot to consider with a saltwater aquarium. Just go slow and build up a little at a time. There’s a lot to think about here so take it all in and then research areas where you have questions. It sounds harder than it really is.

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