Marine Aquarium Do's and Don'ts for beginners

Marine Aquarium Do's and Don'ts for beginners

Over the years I have come across a number of helpful do's and don'ts for marine aquarium keeping that would have saved me a lot of time, money and disappointments. If only I had them all together in a list from the start!

Well here they are - I have decided to jot a few of them down in the hope that they will save at least one new marine aquarist some time, money or disappointment.

This is only a very basic guide and is not meant to be conclusive or detailed – just a memory jolter in bullet point form that you can refer to every now and then to refresh your memory. I encourage you to research in more detail any and all of these points using your favourite marine aquarium book or even the internet!

The Do’s
•Do buy a good book on marine aquarium keeping. This should be your first purchase and most valuable accessory!
•Do look at your tank every day to check your fish and invertebrates health. Are they acting differently than normal, do they have any damage or signs of illness etc
•Do react quickly when you think something is wrong. Test your water quality and conditions. Look for indicators of problem or disease. Read your aquarium books, search the internet and talk to your friendly marine aquarium retailer for advice.
•Do create a maintenance schedule that helps you remember to regularly check your water quality, top up with freshwater, replace saltwater, replace consumables etc
•Do feed small amounts of food regularly
•Do feed a varied diet that accommodates all your inhabitants needs
•Do ensure you have adequate filtration (biological and/or mechanical)
•Do ensure you have sufficient circulation in your tank. Most people recommend at least 10x your tanks volume be circulated every hour. This includes powerheads, filters (both internal and external), protein skimmers, circulation pumps etc.
•Do use a timer if possible on your tanks lights as the inhabitants like regularity with respect to their daytime and night-time.
•Do adopt a photoperiod that considers the output and intensity of your lights and either mimics the inhabitants natural environment or that of your local environment
•Do wash your hands before putting them in the tank or working with any equipment that will come into contact with your tanks water. Soaps, creams, medicines etc can all harm your inhabitants.
•Do use good quality activated carbon in your tanks - this removes unwanted toxins and keeps the water crystal clear.
•Do regularly replace your activated carbon (approx. every 8 weeks)
•Do keep your tank as close as possible to Natural Sea Water conditions (NSW). These are, for the most, a pH of 8.3, Specific Gravity (SG) of 1.025, temperature of 25 degrees Celsius. There are many other levels that need to be considered (eg Calcium, Carbonate Hardness, Iron, Silicon, Phosphate, Copper etc) but these are the main ones.
•Do acclimatise your new fish and inverts appropriately - your marine aquarium retailer should notify you of their requirements as they can vary from 10 minutes just for temperature adjustment for hardy fish to hours for sensitive inverts.
•Do use, where possible, natural sea water in your tank - there is nothing like the real stuff!
•Do make sure you know where the real sea water is coming from - you don’t want it to have been collected in your local marina or just offshore as it will not be suitable as it will contain all sorts of man made pollutants.
•Do use RO/DI (Reverse Osmosis/Deionised) water when real sea water is not available. Use it to top up or when mixing new salt - especially in tanks that contain corals and other sensitive invertebrates.
•Do use a protein skimmer if possible. It complements your mechanical and biological filtration and in some cases is a mandatory requirement for keeping certain inverts.
•Do ensure you understand the nitrogen cycle. This is the fundamental basis for how wastes in the aquarium get converted from toxic chemicals (ammonia and nitrites) to less toxic chemicals (nitrates) by bacteria that live in your water.
•Do select your new fish and inverts very carefully. Ensure they are not damaged, diseased or otherwise looking unwell. If possible, quarantine them in a separate tank before adding them to your main tank. An alternative is to use an Ultraviolet (UV) steriliser for about four weeks after adding the new inhabitants to kill off any newly introduced diseases.

The Don’ts

•Don’t overfeed. This is most probably one of the most common mistakes for a beginner. Fish always appear hungry and it is very tempting to feed them often but this can cause all sorts or problems – the most common being poor water quality. If nor corrected this can lead to sickness and death of your fish and inverts in a short time. If you are going to very often then ensure you only feed small amounts and that it all gets eaten immediately. Also test your water quality often (eg test ammonia, nitrite and nitrates at least a couple of times a week).
•Don’t overstock you tank. This is also one of the most common mistakes for beginners. Tanks can only successfully support a certain amount of life in them and this is based upon a number of factors. Some of these are volume, surface area, aeration, circulation, filtration (mechanical and biological), maturity, quantity and frequency of water changes, flow, number of fish and inverts etc etc. It is better to start slow and small and build your way up. Talk to your local marine aquarium retailer for advice on stocking levels.
•Don’t rush the maturation of your new aquarium. This is another one of the most common mistakes for beginners. Sea water is a complex living thing. It contains thousands of elements, compounds, minerals and organisms that are all reacting together. When setting up a new aquarium it takes time to mature enough to sustain higher order living animals such as fish and inverts. Generally it can take up to eight weeks for the nitrogen cycle to complete and the sea water stabilise enough to allow for the addition of fish. A good idea is to stick to one or two hardy fish initially and then slowly add more fish over a period of time, all the time keeping a very close eye on water conditions. I would be testing daily for pH, salinity (SG), ammonia, nitrites and nitrates during this phase. After six months or so if everything is going all right I would then consider basic, hardy invertebrates such as soft corals, algae’s, shrimps, anemones, star fish, urchins etc. After these have been living successfully for a while (after about one to two years) I would then consider the more sensitive inverts such as stony corals, clams etc.
•Don’t mix inhabitants (fish or inverts) without some research of your own and/or advice from your local marine aquarium store - they don’t all get on together – even if they look weird or wonderful and you just have to have it!
•Don’t change any critical aquarium conditions too drastically - stability is your friend. The main ones include salinity (Specific Gravity or SG), pH and temperature.
•Don’t use water from your tap without treating it and testing it. Some local water supplies have unwanted chemicals such as copper (Cu), Iron (Fe), Ammonia (NH4), Nitrites (NO2), Nitrates (NO3) and heavy metals in them. They all have chlorine and chloramines in them and need to be removed before being added to the aquarium (or even mixing salt in - remove the chlorine first).
•Don’t use fly sprays, air fresheners, incense etc in the same room as your fish tanks as they may well poison your inhabitants
•Don’t use the cheap types of hydrometers to measure your Specific Gravity (salinity) as they are inherently inaccurate! These include your common floating type (they quite often also contain a thermometer in them as well) and the floating needle types that stick to your glass and a little plastic needle floats in the water indicating your SG! These types are also affected by temperature and may be giving an incorrect reading is not used correctly. I find the most accurate is a refractometer and they are not too expensive (approx $100)
•Don’t use only one powerful heater in your aquarium. It may save you a little money but if it breaks (turns off, or even worse gets stuck on) you could lose everything. Preferably use two smaller heaters so that if one breaks you have a back up and if one gets stuck on it won’t cook your fish.
About the Author
Doug Kamp has been keeping aquariums for 30 years, the last 15 of those being mainly marine aquariums. Doug is the proprietor of Aquariums Online which is an online mail order business based in Perth Australia. This article, and others can be found at

About the Author

Doug Kamp has been keeping aquariums for 30 years, the last 15 of those being mainly marine aquariums. Doug is the proprietor of Aquariums Online which is an online mail order business based in Perth Australia

Doug Kamp