Reef Tanks On A Budget (Part 8): Livestock (Coral + Fish)

Reef Tanks On A Budget (Part 8): Livestock (Coral + Fish)

In the 8th installment of this multipart series, Reef Tanks on a Budget (Part 8): Livestock, Coral & Fish, we will go over clean-up crew, fish and coral options.

Editor’s Note: If you haven’t already, please give Part 1, 2, 3, 4, 5, 6 and 7 a read first:

When starting a reef tank, the first thing you imagine is all the types of fish and coral that will be in your little ocean at home. After setting up the aquarium, aquascaping it and waiting for it to cycle, it’ll finally be ready for some livestock. The question now is: what do you add?

Clean-up Crew

Clean-up crews are invertebrates that help maintain a thriving reef by eating algae and removing waste or detritus. Before selecting invertebrates for your clean-up crew, make sure they are reef safe and that they will not catch and eat live fish. It is also important not to add too many as they will due to the lack of a food source increasing ammonia, nitrite, and nitrate.

Here are some of the most popular options and a general recommendation for how many you’ll need:

  1. Crabs: Popular options include red-legged hermit crabs, blue-legged hermit crabs, emerald crabs, sally lightfoot crabs, and arrow crabs. Emerald crabs are known to eat bubble algae, and arrow crabs are known to eat bristle worms.
    Recommended Quantity: 1 for every 10 gallons of water.
  2. Snails: Snails help clean rocks, pumps, and the glass or acrylic walls of the aquarium. Some will even sift the sandbed, eating food and detritus that falls to the bottom. Some examples include Turbo snails, Astraea snails, Trochus snails, Nerite snails, and Nassarius snails.
    Recommended Quantity: 1 for every 10 gallons of water.
  3. Shrimp: Shrimp are a great addition because not only will they help clean up uneaten and decaying food, many will also help clean your fish and even eat Aiptasia!  Some examples are skunk cleaner shrimp, blood-red fire shrimp, peppermint shrimp, and banded coral shrimp.
    Recommended Quantity: Variable depending upon the type of shrimp.
  4. Sand-sifting Sea Stars: As the name indicates, these inverts clean and stir the sand in search of food. Add only to well-established tanks with stable water chemistry.
    Recommended Quantity: 1 for every 50 gallons of water.
  5. Sea Urchins: Will consume detritus, algae, leftover food, and even dead fish.
    Recommended Quantity: 1 for every 200 gallons of water.
  6. Sea Cucumbers: Sea Cucumbers act as a vacuum, sucking up detritus and filtering the substrate. Recommended for expert hobbyists with established reef aquariums only.
    Recommended Quantity: 3” of worm for every 20 gallons of water. (In many cases, they can grow up to 12-18” long.

Budget Recommendations:  Start with just crabs and snails as this will generally be adequate to help keep algae and detritus under control. Some of the other cleanup crews are fun to have but not necessary.


When choosing fish to add to your reef tank, it is vital to make sure that fish is compatible with the other fish you would like and safe around the corals and other invertebrates you would like to keep.

Keep these things in mind when purchasing a new saltwater fish:

  1. Size/Length: The rule of thumb is 1 inch of fish per every 3-5 gallons of water.  For example, a 120-gallon tank can have 25 – 40 inches of fish. Think long term and use the size that the fish can become instead of its current size.
  2. Reef Safe: Is the fish reef safe or reef safe with caution? Some fish breeds sold as reef safe may nip at corals and eat your clean-up crew.
  3. Temperament: Will the new fish get along with other fish or aggressively compete with them for food? Nobody wants to spend money on fish just to have it kill or get killed by the other fish in the aquarium.

Budget Recommendation: To save money, buy small and let the fish grow into the tank; however, don’t save money by purchasing from a questionable supplier. Make sure to buy from a reputable source that quarantines before the sale and only offers healthy fish as adding a sick or diseased fish can wipe out an entire system.


Live corals are usually added after the clean-up crew and fish as they are more sensitive to changes in water chemistry like pH, calcium, and alkalinity. Only once the proper levels are stable should coral be added. We recommend starting with something easier to care for, like Zoanthids or Mushrooms, and over time transitioning to more difficult corals like small polyp stony (SPS) and large polyp stony (LPS) corals.

Types of corals and how difficult they are to keep:

  1. Soft Corals: These are usually the hardiest types of corals to keep in an aquarium. They do not consume much calcium and alkalinity, and they can withstand slight swings in parameters better than most hard corals. Examples: Zoanthids, Xenia, Leathers, and Mushrooms.
    Level of Difficulty: Easy
  2. Large Polyp Stony Corals (LPS): A type of hard coral, LPS corals use calcium carbonate to build their coral skeletons. They generally do well in systems with some nitrates and phosphates and can do well under less intense lighting than SPS corals.
    Examples: Brain, Frogspawn, Hammer, and Euphyllia.
    Level of Difficulty: Moderate

  3. Small Polyp Stony Corals (SPS): Small polyp stony corals are susceptible to high nutrients (nitrates and phosphates) and varying parameters like calcium, alkalinity, and pH. They also require more light than soft and LPS corals. Most aquariums should wait six months to a year to stabilize before adding SPS corals.
    Examples: Acropora, Montipora, and Staghorn.
    Level of Difficulty: Difficult
  4. Non Photosynthetic Corals (NPS): NPS corals do not need intense lighting since they are not photosynthetic; however, they require pristine water conditions, and in many cases, will need direct feeding.
    Examples: Tube Coral, Flower Tree, and Sea Fan.
    Level of Difficulty: Difficult

Budget Recommendation: Most corals can range from a small frag or specimen to a large colony. To save money, purchase a small version of the coral you want and let it grow out. These frags will cost a fraction of a larger colony and generally have a higher survival rate.

When purchasing livestock, it can be hard to stay on the budget. To save money in the long term, buy small, healthy, and pest free livestock. If you have any questions or need assistance with your reef tank supplies, please contact us for more information about our products. Happy Reefing!

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