Hi,
To start if you want Clownfish, it's a minimum of 30g tank required. The bigger the better. Have a read of this, there are some mistakes that need creasing out but they're only minor. This is for a VERY basic setup.
SIMPLE TANK SET UP
This setup is the simplest setup you can have, and is only possible on small tanks of 155 litres or less. It’s important to remember this is the bare minimum setup and it will normally not be as easy to maintain than if you were to use a more advanced system setup such as a sump.
What is also important to understand is that this setup will require more cleaning and will minimise the number of fish you can keep.
Why? Within a marine tank, your fish, coral and creatures will consume the natural nutrition which is held within the water. These nutritional elements within the water are crucial for good health, growth and colouration. In smaller tanks there is less water and therefore the resources from the water will be used at a faster rate. Without some of these elements, the water quality will decrease, which can cause symptoms such as low PH which in turn can cause death. This is why we do water changes.
Each fish/animal will produce a bio load, which contains ammonia. Ammonia is extremely toxic to fish, and will, if left high, kill them pretty quickly. Ammonia, nitrates, and nitrites are toxic and harmful to inverts and fish. The ways which we counter these, with this type of setup up, is through the live rock, which is a natural filter which removes these toxins. The filter pump, and protein skimmer help clean the water, and add beneficial help to the live rock. The filter pump is useful for running phosphate remover, bio cylinders, carbon etc.
BASIC EQUIPTMENT LIST
- A tank no more than 155 litres.
- A filter pump suitable for marine systems. This should be able to filter the water, and remove/reduce any ammonia and nitrates that are harmful to your aquariums live stock. I recommend the FLUVAL 400 series for most systems but any similar filters should be adequate. (optional, but highly recommended)
- A Protein Skimmer. This is a smaller filter pump which uses air bubbles to help maintain clean water. This is especially essential for those of you who wish to stock corals, and inverts.
- A Heater. This is needed to keep your tank at the correct temperature. A reef system should be kept between 75° - 80° and a fish only system at the same.
- A Powerhead. This is a type of fan which is used underwater and used to create a flow in the system. This is important to keep the fish happy in their environment, to oxygenate the water, and for coral health. Dependant on the setup and tank size you may want to get two.
- Lighting. This will depend again on your tank setup. For soft corals, most LPS and some (minimal) SPS corals 2x T5’s will be perfectly acceptable. If you want anemones and/or to maximise your coral options/ corals health then you can go for 4x T5’s or metal halides. T8’s are the minimal lighting I would recommend for corals, and fish. The less the volume of water, the less light you require.
OTHER STUFF
- A thermometer to ensure your heater is working and temperature is correct.
- Food, for fish, and corals. Marine fish food should consist of live, frozen and flake/pellet food. Marine snow/calcium/copepods for corals.
- Test kits for Ammonia, Nitrates, Nitrites, and PH as a minimum.
- Refractometer for measuring the salt to water ratio. Should be between 1.024 - 1.027.
STOCKING
- Live Rock is essential for these size tanks as it is the main filter for the water and will remove ammonia and nitrates. A filter pump will not be enough on its own, and will require quite some quantity of live rock to filter it. You should aim for aprx 1 pound (minimum) - 1.75 pounds per gallon of water.
- Corals are not really restricted with the tank size, and provided filtration is good then most corals will thrive provided lighting and water quality is adequate.
ADVANTAGES
- Minimal costs compared to other setups.
- More space under the tank, and easier to move.
DISADVANTAGES
- Harder to maintain as you will need to clean filters, and test more often.
- Harder to correct an issue if it arises. Basically this issue comes with having a smaller tank, if something goes wrong, it becomes a problem quicker as there is less water and therefore takes less time to go wrong.
- You will want BIGGER! As soon as you buy your tank, you will want bigger. Smaller tanks limit the fish you can stock, and the quantity you can have. For example you cannot keep Tangs, (EG. Regal Tang, Dory from Finding Nemo)
SYSTEM MAINTENCE
This varies from system to system and each reefer may advise differently however in a reef tank filtered by a pump and protein skimmer your tank maintenance will increase.
DAILY -
1. Test water parameters for Ammonia, Nitrate, Nitrite, and PH (as the bare minimum)
WEEKLY -
1. Clean Filter pump
2. 10-20% Water change.
3. Clean/empty protein skimmer
4. Test Salinity.
MONTHLY -
1. Change supplements in the filter pump (normally bio cylinders, carbon, etc)
to the salty side of the forum 
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