Reef Janitors – Essential In A Saltwater Aquarium

Stability in the saltwater aquarium is key to success (as well as research and patience). Stability is created by the aquarist and the filtration within the aquarium.

The aquarist provides assistance in this area by ensuring that the correct care and maintenance is provided to the aquarium.

The filtration within the aquarium allows for pollutants within the water to be processed, therefore producing a pollutant free environment.

In the aquarium, however there are areas where Mother Nature can help a bit more!

If you are keeping fish then they are going to produce waste, corals produce waste as well albeit to a lesser degree plus the food you add to the aquarium is not always eaten. All of this puts additional strain onto the aquarium filtration system.

For the purpose of this post I will assume that live rock is being used as the filtration method.

Live rock requires good water flow around, over and into the rocks so that the bacteria can process the ammonia, nitrite, nitrate and to a lesser degree phosphate.

Live rock and any other filtration medium cannot process waste until it is broken down. So why wait for the waste to break down – remove it.

There are manual ways in which this waste can be removed. A good example is during a water change. You can gently blow the rock face; stir the sand the siphon the detritus etc out of the aquarium.

Great the waste has been removed from the aquarium and will not now break down.

But you will not get all of it. What about under the rocks, behind the rock, inside the nooks and crevices. There is no way you are going to get it all.

No matter how much water movement you provide or how careful you are there is going to be waste/detritus within the aquarium.

It is a confined environment, there is nowhere for this waste to go except to be broken down and converted by the filtration process.

I am not saying that you should not remove waste as part of your water changed. Of course you should – this should be standard practice.

How about having your aquarium cleaned continuously by Mother Nature?

This is exceptionally easy to achieve and there are lots of animals who are willing to take on the task of cleaning your aquarium on a continual basis.

These animals are hermit crabs, snails etc etc.

They are commonly know in numerous terms by aquarists. Terms such as ‘reef janitors’,’reef critters’,’clean up crew’ and many more.

On the natural reef how many of these animals do you think there are?

Millions upon millions all keeping the ocean floor, reef face etc clean.

So which ones should you use and how many do you need.

A lot of this depends upon what you require cleaning in the aquarium.

There are animals which like to eat algae, others which eat detritus and others that eat waste.

I shall cover a few of these below:

Astrae Turbo Snails

Very good at consuming algae preferring diatom algae as well as some types of cyano

Calcinus Hermit Crabs

Fast consumers of detritus as well as various flavours of algae and cyano.

Red Leg Hermit Crabs

Superb scavengers which will eat as much uneaten food in the aquarium as they can locate. They also sometimes eat algae.

Nassarius Snails

This type of snail burrows into the sand and consumes as much detritus and waste as it can locate. The may sometimes consume algae but are better at scavenging. They are great additions to a deep sand bed.

Cerith Snail

These types of snails will eat waste and algae from all types of surfaces. Due to the small size of their shell however they can become a target to blue leg hermits if they are kept in the same aquarium. The hermit will eat the snail and move into the shell.

Blue Leg Hermit Crabs

Blue leg hermits are superb scavengers. Due to their small size they are able to get into the areas of both the aquarium and live rock which others cannot reach.

Arrow Crab

An excellent scavenger in the aquarium plus as an added bonus they are partial to bristle worms.

Emerald Crab

The emerald crab is known for its taste in bubble algae which is also known sometimes as sailors eyeball.

Sally Lightfoot Crab

The Sally Lightfoot Crab is a good looking crab and is an excellent scavenger in the aquarium.

Cleaner Shrimp

As per their name they love to clean. They are great scavengers plus they will also clean your fish. Stick your arm in the aquarium and they will also attempt to clean that – trust me it feels very strange!

Linckia Starfish

Attractive scavenger which feeds upon algae film as well as detritus. They are also partial to the occasional feeding from the hand of the aquarist.

Sand Sifting Starfish

A fantastic addition to the aquarium to clean the sand. They will actively burrow through the sand cleaning it as they go.

Cerith Snails

Active cleaners of the glass removing diatom based algae. As well as cleaning the glass they also sift through the sand in search of algae.

Trochus Snail

These snails like to be provided with places to hide, for example in holes between rocks etc. They consume algae, cyano and diatoms and are very good at removing film algae from the glass.

The above list is in no way complete. There are many, many more animals which can be added to the aquarium to assist in the cleaning process.

The trick is adding the animals which have the eating habits which are both correct and beneficial to the aquarium system.

The addition of the ‘clean up crew’ depends upon the individual requirements of the aquarium. If you introduce them to soon after cycling then there may not be enough for them to eat. If you add them to late then there may be too much waste for them to cope with.

So I guess the question here is ‘how many should you have?’

There is not definitive rule of thumb here but there is a general one which I follow. This general rule is:

  • 1 crab for every gallon
  • 1 snail for every 1.5 gallons

The addition of other animals depends upon the individual requirements and the cleaning requirements of the aquarium.

I cannot emphasise enough how important and beneficial it is to add these reef janitors to your aquarium. They are amazing animals to watch and you can get some great close up pictures of them if you so wish.

This is not the reason we purchase them though. We purchase them for their cleaning abilities. Without them the aquarium will slowly accumulate waste in the aquarium which the filtration will do its very best to process after it has broken down but as already said why let it have to break down at all.

Nature is very powerful, let it do the work for you and clean your aquarium.

On a final note it needs to be said that the addition of reef janitors to the aquarium should in no form replace the care and maintenance of the aquarium. They are an addition to the aquarium to make it cleaner – there is still a requirement to care for and maintain it.


Rate this post
2 Comments
  1. Wow this is a great resource.. I’m enjoying it.. good article

  2. Thanks for sharing this wonderful information, I’ve bookmarked your site and will visit it often.

Leave a Reply