Cloudy aquarium water, oh no!

Oh no indeed! If you have cloudy aquarium water, its bad bad bad!

Sure, am sure thats not news to you but who knows, it may be the first time you see it and you are panicking right?

Well firstly lets talk about fixing cloudy aquarium water and then about preventing it.

Fixing Cloudy Aquarium Water

Well fixing cloudy fish tank water is pretty simple.

You got it, change the water!

The easiest thing to do, is to
1) first catch your fish using your fish net (and hopefully they are not already sick) and place them in a pail of treated water. Treated water here means clear tap water that has had anti-chlorine/anti-chloramine already mixed in.

2) Dont forget to have your air bubble in the pail as well. You can either use your fish tank air pump or this is a good time to use that battery operated air pump you have lying in the closet (Now how did I know you have one? :) )

3) Last but not least, cover the pail with something so that the fish does not jump out. Speaking of jumping out, there are probably 2 reasons why a fish might jump out.

The first is that the fish is a jumper! You dont really need to worry about that.

The second is because it has some sort of discomfort which usually means the water is not treated right or perhaps there are too many fish in the pail. So do take note.

4) Once you got all the fish out, you can drain the water away completely. See an easy way from my fish tank cleaning page.

5) Now the nasty thing about cloudy aquarium water is that likely the water quality has gone to the pits. So you would need quite a bit of rinsing (which means washing the aquarium a few times and emptying a few times). I tend to think that all that chlorine in tap water will help to weed out all the nastys that were left behind. Be thorough.

6) The other bad thing that cloudy fish tank water does is, its probably messed up all the good bacteria in your filter too. You may want to rinse this down as well.

7) Now all this rinsing has probably done a good job of cleaning the bad stuff from your aquarium. The problem you now have is how to get your biological filtration up and running cos dont forget you got a bunch of fish in the pail!

Well, heres where having bottles of cultured 'good bacteria' around is handy. Obviously, you dont want to have this stuff literally lying around, cos you dont want little kids or even worse a baby getting their hands on it, so do be careful.

Having said that, there are commercially available cultures, (both aerobic and anaerobic bacteria) that you can lace your filter media with, and therefore get that biological filtration up and running almost instantly without needing to do any aquarium water cycling.

8) So once you have done that, you can introduce new tap water into the fish tank, treat it with your anti-chlorine/anti-chloramine and I would also recommend to put preventive doses of anti-bad bacteria and anti-parasitic medication.

9) You can then re-introduce your fish, and you should be good to go. Do monitor maybe the next hour or so to ensure your fish are swimming healthily. The true test, is to put some fish food in and observe that they are all eating the food fine.

Preventing Cloudy Aquarium Water

Having spoken about how to fix cloudy aquarium water, moving on to how to prevent cloudy aquarium water is much more invigorating. I must say, and this is not arrogance, I have not had cloudy aquarium water in probably 2 decades or more.

The critical question is,
why do we get cloudy aquarium water in the first place?

There are basically 2 reasons. I am sure there are many other sub-reasons but these are the 2 main ones.

1) The first reason is feeding.

If you are feeding your fish more than they can eat (and the tropical fish you have are the type that dont gorge themselves like Koi), all the uneaten food will remain either floating at the top or fallen to the bottom.

If you dont have any bottom feeding fish like catfish, then the fallen food will break up and become part of your gravel and aquarium sand.

Now just like anywhere else in the world, when there is uneaten food, something will come by to feed on it. Generally for aquariums, this means bacteria and bad bacteria at that.

Even if they are not bad bacteria, they will cause discomfort to your fish and any discomfort can lead to a lowering of the natural defenses of the fish and for sure you will start to see some sick fish. A favored illness will be cloudy eyes but anything goes really.

2) The second reason is likely you do not have an efficient method of cleaning or removing waste or uneaten food.

So the 2 above form a self-fulfilling prophecy of illness for your fish and ultimately death and stinky water. Not good.

So how do you fix this?

a) Well firstly obviously, dont overfeed your fish!!

Feeding fish is more of making sure that there is just enough food for everyone. Its not about making sure they are full and definitely not about 'leaving some food about in the water just in case they get hungry', like we would do for our dogs and cats and I guess our kids (food in the fridge). Its in fact better to under feed your fish (but not your kids!).

This means you need to monitor your fish and determine what is the optimal amount. A sure sign of overfeeding is when the fish no longer bother about the food that is still floating in the fish tank.

When you see this, do remove the food. No exceptions. Just remove them with your fish net. This will save you a ton of headache later.

b) Secondly, you need a better filtration system!

Likely you have one of the cheaper or less effective filters available. Try to invest in some sort of external filter which perform much better filtration. Also, having a good understanding of your filter media, will mean a huge difference to the health of your fish.

c) Thirdly, invest on having some bottom dwelling fish such as catfish. Plecos are commonly thought to help in this sort of "trash management" but I have found that this is not true for healthy and clean aquariums. In fact, your Plecos could die if you think they are doing this in a clean aquarium! You need actual catfish of some sort such as Synodontis.

So if you ensure the above 3 items, namely dont overfeed your fish, have a good external filtration system and have some bottom dwelling fish, chances are you should never ever get cloudy aquarium water again.

Good luck.

Return from cloudy aquarium water to fish tank maintenance

Return to tropical fish catalogs