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How to Set up Your First Marine Reef Aquarium

A passionate aquarium enthusiast with over 35 years in this hobby, I have gone the entire distance.

The Four Critical Requirements for Marine Reef Fish

Marine reef fish are the most colorful of all fish, and setting up and maintaining your own marine reef aquarium will give you tremendous satisfaction and years of viewing pleasure. For most of us who have previously kept freshwater fish, keeping marine fish is the next level in terms of challenge—both for the budget and the knowledge that will be required to ensure that we meet the aquarium inhabitants' needs.

The environment in coral reefs is one of the most stable environments, and that only means that these fish have exacting requirements that must be met. Yet, having said that, the good news is that this can be easily replicated in your home aquariums. Let's understand some of the basic requirements of these beautiful creatures:

1. Temperature

The ideal temperature for all tropical marine fish is 24–25 degrees Centigrade (75-77 degrees Fahrenheit). This can be maintained either by use of chillers or thermostats, depending on the climate in your geography. Most marine reef aquariums in tropical areas are in residences where the air-conditioning itself helps. It is, however, important that the aquarium is set up in a place where it will be away from drafts or direct sunlight, which will affect the ambient temperature.

2. pH and Alkalinity

The ideal pH is 8.2 and above. This is normally achieved with the synthetic salt mix added to freshwater.

3. Light

Coral reefs develop only under specific conditions—apart from the temperature and pH, light is most important. The light must reach the coral inhabitants, as corals harbour photosynthetic, symbiotic algae (zooxanthellae) which are critical for the reef's health. Metal Halide lights and T-5 lights help replicate this.

4. Water

Water has to be clear and sediment-free. This is achieved with the help of a 'sump' tank, which is a specially created filter tank that keeps the live rock and other filter media that harbour the nitro bacter. External filters can also be used in combination with the sump; however, it is not recommended to do so without the sump.

The sump custom-built for this setup was 40 in x 18 in x 15 in (L x W x H).

The sump custom-built for this setup was 40 in x 18 in x 15 in (L x W x H).

Here's a Video of the Reef Tank and the Sump Setup:

How to Ensure Your Aquarium Meets the 4 Requirements

Having understood these four critical requirements, let's understand how we can achieve the same in our aquarium.

Aquarium Size

A minimum size recommended is ideally 3 ft x 2 ft x 1.5 ft ( Length x Width x Height). The bigger the size, the better it is in stabilizing water conditions. However, one can also achieve good success with smaller aquarium sizes (Nano Tanks), although, it is important that Live rock is part of the main setup to stabilize the environment. Remember...the bigger the tank...the better!


This is a small aquarium tank that is placed below the main tank for filtering the water. One of the most important components of the marine aquarium, which harbours the nitrobacter and plankton which are essential for controlling the nitrogen cycle in the aquarium. These prevent the build-up of ammonia & nitrates. The sump also provides additional water volume and a 'refuge' for the microorganisms & plankton to culture.

Protein Skimmer and Return Pump

A protein skimmer is a device used to remove organic compounds from the water before they break down into nitrogenous waste. Protein skimming is the only form of aquarium filtration that physically removes organic compounds before they begin to decompose, lightening the load on the biological filter and improving the water's quality. The skimmer is usually kept in the sump itself, but can also be attached separately to the main tank. The skimmer used in this setup is a Reef Octopus skimmer.

Sea Salt Mix

For creating the ideal marine water. Numerous brands are available, my favourite is 'Red Sea'.

Live Sand and Decorations

'Coral Reef' is a good brand, supposedly the sand is from the Red Sea and is supposed to have beneficial bacteria. I usually use this in combination with crushed coral gravel for the background base, with the finer live sand in the front.

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One can keep an open tank and an overhanging lighting fixture (strong lighting is essential if one plans to keep live corals and other invertebrates). A combination of Metal Halides (20000K) along with T-5 and Blue LED's will be best. There are a lot of options available here, especially in the new generation LED's which give max lighting and minimum water loss due to heat.

Live Fish and Anemones

These are expensive compared to Freshwater and as such one needs to budget for them separately. My advise is to build up the livestock gradually over months as it gives the aquarium time to adjust the Bio Load (apart from being lighter on the pocket as well). Avoid the temptation of adding a lot of livestock immediately to a new tank. The above setup was kept for cycling for a good 2 weeks before we added the first few fish to it (4 Blue Damsels) and then gradually added livestock over 2 months. Do note that some fish are under the endangered species list (ref CITES) and it is the responsibility of the buyer to ascertain this and not encourage the trade in such species. It is advisable that one studies the compatibility of fish and the invertebrates, before going on a buying spree.

Step-by-Step Instructions for Creating Your Aquarium

Assuming that you have got all the 'ingredients' for your marine reef project ready . . . let's start putting them together to create an ideal environment for its inhabitants.

  1. Mix the synthetic salt mix with the recommended amount of water, ideally 1 Kg of salt to 30 Litres of de-chlorinated RO water. The above aquarium setup was close to 500 Litres capacity, not including approximately 100 Litres capacity in the sump and required 20 Kg of marine salt.
  2. Check the specific gravity of the water. Specific gravity measures the salinity (amount of dissolved salts) in your aquarium water. It is important to periodically measure specific gravity on a regular basis, as this is crucial to maintain the ideal environment for your marine aquarium. You can use a hydrometer to measure specific gravity. The ideal specific gravity level for a Reef aquarium is between 1.023 and 1.025. (Also, keep in mind that when you top up the water to make up for the evaporated water, do so with clean fresh water and not with salt water. When water evaporates from the aquarium, it leaves the salts behind.)
  3. Add the substrate to the aquarium (crushed coral sand/aragonite/live sand). Have the crushed coral towards the back of the aquarium to support the weight of the live rocks and other decorations, while the finer sand comes up in the front.
  4. Start placing the live rocks carefully, taking care to ensure that they are stable and suitably anchored. These rocks are heavy and in case they slip and hit against the glass, it may lead to a crack. One does get special epoxy to glue the live rock together and it is recommended that we use it.
  5. Once the live rock has been placed, slowly start adding the prepared salt water. Keep a saucer or a deep dish on the gravel and pour the water on it to avoid disturbing the gravel and clouding the water.
  6. With the water filled in and overflowing into the sump below, fill up the sump completely before starting the return pump. Add a few live rocks to the refugium in the sump. I usually add a nitro-bacter starter mix to the sump filter media to kick start the ammonia cycle.
  7. Let the water run continuously between the aquarium and the sump continuously for at least two weeks before adding the first livestock.
  8. This also gives you time to set up the lighting and other accessories and also take care of any leakages or surprises that invariably crop up.
  9. Post two weeks, do a water test to check on critical parameters like: Salinity, Ammonia level, Nitrites, Nitrates and pH. If everything has gone as per plan, this should be your reading: your Salinity should read between 1.023 - 1.025, your Ammonia, Nitrites, and Nitrates should read 0, and your pH should read between 8.2 - 8.5
  10. Time to add your first livestock. (Note: one may choose to add a fish or two post 1 week to speed up the cycling itself, though avoid the temptation to stock a lot of fish at once.)

Final Tips on Backups and Lighting

  • Since you are investing so much in your dream marine reef project, it is advisable to have the entire system on a power backup (UPS/Inverter) to take care of any outages.
  • It will also help to have the lighting on a timer to replicate the natural day/night cycle, with the metal halides coming on towards the afternoon while the T-5 lights come on during the morning and evening.
  • Having the blue LED lights on at night replicates the moon's light, apart from giving the special effect.

Hope you found this article helpful.


Amar Salvi (author) from India on March 03, 2014:

Used a Hailea pump in this one. Capacity 2500 L/H

vasu on March 02, 2014:

hi i have same aquarium size has u have i want to know which pump u have used in ur tank

Amar Salvi (author) from India on November 17, 2013:

I use ADA' NA Water setup for filtering out toxins and other sediments. It does have a separate RO attachment though I haven't used one.

Amar Salvi (author) from India on November 17, 2013:

The crushed coral bed is about 3 -4 inches thick and the live sand in front about 2 inches. For the refugium, I would recommend live rock.

ifigueiredo on August 13, 2013:

Sorry, one other question. Do you use a RO/DI (reverse osmosis deionizer) for your water? How important is the DI part? Thanks.

ifigueiredo on August 13, 2013:

Thanks for the post. I have a couple of questions.

1) you say that you used crushed coral in the back and live sand in the front - can you please confirm how deep (inches) the crushed coral and live sand should be. I assume it would not be a deep sand bed.

2) what do you recommend to put in a refugium? Live Sand? Mud? Macro Algae? Live Rock?

Thank you.


Amar Salvi (author) from India on December 19, 2012:

Thanks,Mits. Appreciate your feedback.

mits on December 19, 2012:

great one... thanks for this!

Amar Salvi (author) from India on October 27, 2012:

Thanks for your feedback,Anna. Definitely encouraging.

Anna on October 21, 2012:

Thanks for sharing this post to us. This will really help people on how to set up first marine reef aquarium. Keep posting!

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