Cloudy water can be from a few things, but mostly it is from the new tank syndrome in newly set up aquariums. This is the result of an imbalance of bacteria, which is growing at different rates during the cycle. As long as you haven't been chucking in handfuls of food it is just down to everything settling in the tank. The main thing is that you don't panic and don't empty the tank. As a last resort, use water clarifying chemicals.

ALWAYS test your water before introducing more fish, the chemistry of your water can change at any time, see water chemistry. The most common cause of this is a P.H drop which is sometimes ignored because all the other fish in the tank look fine. This is because fish acclimatize themselves to problems with their water for a short time, and it is only when new fish you try introduce die that you realize there is a problem with your water.

It is an algae bloom. make sure you figure out what extra light is on the tank, such as a bright window, an open doorway that sunlight comes into, even too much overhead fluorescent lighting as in a school or office building. If you use your tank as a nightlight, don't. If you are not growing live plants, around 8 hours a day is fine. Do some partial water changes & use fresh carbon in your filter.

You overloaded you tank's limit to control a healthy amount of growing bacteria contributed to "new tank syndrome". You need to have patience & add only about 6 hardy fish , then test the water each week keeping a check on the nitrites. Once your tank has gone through the cycle (nitrite levels have been up and gone back to zero) you can then start stocking properly. Expect to have to wait around 4-6 weeks

NO. Only partial water changes are required during regular routine fortnightly/monthly maintenance. You should aim to change no more than 30% at any one time. You can also clean your filter in the old water before throwing it away. (never under the tap) This will ensure that the beneficial bacteria living in your filter will not be destroyed by the chemicals present in tap water.

It is rotted, old food & waste that has spoiled in the tank water and turned to fungus. You need to cut down on the amount of food you are giving and also do a gravel clean every time you do a partial water change.

It is algae. If it is in thick layers or pieces, you might want to first clean it off the walls & plants, do some partial water changes & decide whether or not you have too much direct sunlight or an excessive amount of artificial light. Growing live plants helps to control this too, because live healthy growing plants compete with algal cells for food, therefore reducing the amount of algae in your tank.

It is what we refer to as Ichthyophthirius multifiliis. "White spot" disease or "Ich" is distributed worldwide. It affects all freshwater fish & under aquarium conditions is very virulent. It can attatch itself in the aquarium to such things as gravel or tubing. There it will produce hundreds of young & within 18-21 hours they are released into the water. They actively penetrate the skin & gill & enlarge until they are visible as white spots. Medications are easily available and very effective. Raising the temperature slightly during the treatment will aid in your battle against this protozoan parasite. The use of freshwater aquarium salt is also suggested but check first to make sure you don't have any fish that can't tolerate salt.

Water in various parts of the country may have different pH values. Ranges of 6.5-7.8 for freshwater species is ideal. From the hobbyists perspective, the most practical aspect of water hardness is that softer water has less buffering capacity. This means that pH can drop abruptly in a tank with soft water, whereas pH tends to be stabilized in aquaria with hard water. Too soft can pose management problems, & too hard, the same. Water hardness does NOT change the pH one way or the other, it just affects the water's ability to hold or stabalize pH at one reading. There are plenty of easy to use products available to adjust the P.H and G.H but all must be used in conjunction with the appropriate test kit.

Goldfish need lots of clean fresh water & enough oxygen to survive. Without at least 1 gallon of water for each fish, it will almost always die. Get him at least a small tank with a simple filter, keep it clean as described above & in a cool spot in the house. Basically the same rules apply to goldfish as they do to tropical fish. Bowls are quite simply not adequate for fish, they are also usually unsuitable for fitting a filter into, which is your fishes life support system.

Measure the inside dimensions of the tank in inches. LxWxH. Multiply the length x height x width in feet.(15" would be input as 1.25) Divide product by 6.25 = UK gallons. For example if you need to work out the gallons in a 24" x 12" x 12" tank you would type into your calculator - 2 x 1 x 1 x 6.25 = 12.5 gallons.

This table will give you an idea how much your tank will weigh when full.	Actual Volume			Tank Weight		Water Weight		Total Weight
	Litres	UK Gallons	US Gallons	Kg	Pounds	Kg	Pounds	Kg	Pounds
	27.7	6.1	7.3	5.6	12.3	27.7	61.1	33.3	73.4
	53.8	11.8	14.2	8.4	18.5	53.8	118.6	62.2	137.1
	67.3	14.8	17.8	9.3	20.5	67.3	148.4	76.6	168.9
	101.1	22.2	26.7	15.1	33.3	101.1	222.9	116.2	256.2
	134.7	29.6	35.6	25.2	55.6	134.7	297.0	159.9	352.5
	161.6	35.5	42.7	29.4	64.8	161.6	356.3	191.0	421.1
	303.1	66.7	80.1	72.2	159.2	303.1	668.2	375.3	827.4
	363.7	80.0	96.1	83.9	185.0	363.7	801.8	447.6	986.8

This could mean that your water pump or air pump might not be working properly or the tank is overstocked & the oxygen content of the water vs the amount of fish is insufficient. Test for anything obvious like nitrite or ammonia. Make sure that the temperature is not too high, as this results in less oxygen in the water too. Remedy any of these problems & do a partial water change. The other problem could be disease, parasite infections such as white spot get into fishes gills causing them serious breathing problems.

Everyone has their own opinions on how to go about this, but in the end, sometimes getting a friend or relative to feed them when you are gone can be very deadly. You can try one of the following suggestions. Pre-measure small amounts of food into portions and label them one for each day. Or, buy a well known brand of automatic feeder that you can set yourself to the proper amount of food. Holiday blocks of food are also a good option. Another option is to just buy live foods as they are already portioned out, just tell your fish sitters to pour in one bag a day. It is much harder to overfeed fish with live food as any that doesnt get eaten immediatly will stay alive untill it does.

More importantly is your fishes lighting while you are away, make sure you put a timer on the lighting for your tank, more fish die through the lights coming on and off at unexpected times or not being put on at all than they do through not being fed for a few days.

Snails often browse on plants when supplies of prepared food, dead fish or algae are low. Chemicals for snail control are commercialy available, but many aquarists prefer more natural methods. Their are some fish which eat them, most favourable is clown loach. However these fish do get quite large.

Q. I have a 20 gallon tank that has been set up for 6 weeks, the nitrites are still high and I've done several water changes to lower it. What else can I do to lower the nitrite level?

First of all stop changing the water! In a new set-up it is normal for the nitrites to get high, and every time you do a water change in the first few weeks you are just slowing down the whole maturing process.If you only introduced a few hardy fish in the beginning they will be ok, We recommend our customers to allow the nitrites to go up and then just stop feeding untill the levels have come back to zero. We find this to be the quickest and less stressful method of maturing any aquarium. You could also use one of the many bacteria cultures available to help speed things up.

Rotting barbels are commonly caused by infrequent gravel cleans being done. In other words you need to keep on top of your tank maintenance, a quick couple of scoops of water from the top of the tank are not enough, be thorough with your gravel cleaner every time you do a partial water change.