Cloudy water after water change
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Biulu
the clean guy
Starfish
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Cloudy water after water change
Does anyone have any idea why my aquariums go cloudy after a water change? Usually it is back to clear after 24 hours. Today I did a 25% change on my 75g and cleaned the filter. Now the water is extremely cloudy. I let the water age for at least 24 hours before it goes in my tank, except that I was 4 gallons short so used water direct from the tap (with conditioner). I use Big Al's multi-purpose water conditioner. Is the cloudiness bad for my fish?
Starfish- Veteran Member
- Posts : 1202
Join date : 2013-09-08
Location : Southampton, Ontario
Re: Cloudy water after water change
Cloudy water after a water change can happen; the cloudiness is often the result of dissolved organic compounds in the water. A bacteria bloom occurs resulting in the cloudy water. It should clear up in a day
the clean guy- Angel Fish
- Posts : 296
Join date : 2013-09-08
Location : Ottawa
Re: Cloudy water after water change
I always get cloudy water when I do a water change in my sand substrate tank. It doesn't matter how careful I am, there are always particles flying up in the water, making it cloudy....
Biulu- Support
- Posts : 3694
Join date : 2013-09-12
Location : Montreal, Quebec
Re: Cloudy water after water change
My tank is gravel, so I can't blame it on sand.

Starfish- Veteran Member
- Posts : 1202
Join date : 2013-09-08
Location : Southampton, Ontario
Re: Cloudy water after water change
Interesting topic. When I change the water in the 55 gallon, which has river stones, I never have any cloudiness. When I change the 5.5 gallon, however, which has plant substrate, I always get a bit of cloudiness. And, again, whenever we change the 220 gallon, which has sand, we always get a lot of cloudiness. The weird thing is, with the 10 gallon, which also has sand, though a softer sand than the 220, it never seems to get cloudy?!
I have never really worried about it, it does not seem to bother the fish, and it always clears up in no time. I always just assumed it had to do with distrubing the substrate, and the total make-up of the substrate (maybe some types of substrate hold in more gunk than others which gets released with the pressure of a WC?!)...likely a lot of stuff in there just waiting to 'swim' out! Now that it has been brought up, I do wonder what the real reason is for cloudiness versus no cloudiness!
I have never really worried about it, it does not seem to bother the fish, and it always clears up in no time. I always just assumed it had to do with distrubing the substrate, and the total make-up of the substrate (maybe some types of substrate hold in more gunk than others which gets released with the pressure of a WC?!)...likely a lot of stuff in there just waiting to 'swim' out! Now that it has been brought up, I do wonder what the real reason is for cloudiness versus no cloudiness!
Shell- Lead Moderator
- Posts : 2607
Join date : 2013-09-06
Location : Nova Scotia
Re: Cloudy water after water change
Well my tank is clear again today. All occupants look fine. I don't know why it does this. I just have to make sure I clean the tank at least a day ahead if we are having visitors. Can't have a cloudy tank on display.
Starfish- Veteran Member
- Posts : 1202
Join date : 2013-09-08
Location : Southampton, Ontario
Re: Cloudy water after water change
I had the same problem with cloudy water when I changed the water in my tanks, many years ago. I bought a diatom filter to "polish" the water. This was a hyper fast and very turbulent filter, but it cleared the water in no time. It seemed traumatic for the fish though, especially in the smaller sized tanks. I do miss my diatom and wish I had not discarded it along with so many Aquaclears, years ago. You can get "water polishing" out of some of the canisters now, but I remember the diatom so well.
alexmtl- Veteran Member
- Posts : 3274
Join date : 2013-09-07
Location : Montreal Quebec
Re: Cloudy water after water change
I remember those as well, did a great job.alexmtl wrote:I had the same problem with cloudy water when I changed the water in my tanks, many years ago. I bought a diatom filter to "polish" the water. This was a hyper fast and very turbulent filter, but it cleared the water in no time. It seemed traumatic for the fish though, especially in the smaller sized tanks. I do miss my diatom and wish I had not discarded it along with so many Aquaclears, years ago. You can get "water polishing" out of some of the canisters now, but I remember the diatom so well.
Actually I saw one of those old glass ones on kijiji recently and almost picked it up.
Steve
Sbenson11- Support
- Posts : 2627
Join date : 2013-09-08
Location : Mt.Pearl, Newfoundland
Re: Cloudy water after water change
I have AquaClear HOB filters on most of my smaller -50 gallon tanks.
I pull the filter and add filter floss/polyester pillow filler to the HOB and in a couple of hours I can see an improvemnent.
IHTH
I pull the filter and add filter floss/polyester pillow filler to the HOB and in a couple of hours I can see an improvemnent.
IHTH
Re: Cloudy water after water change
I have an AC HOB on my 29g and a Fluval canister on my 75g. I use the pillow filler in my canister. However, both tanks are cloudy for a day after a water change. Seems the more water I change out, the cloudier they will be.mikebike wrote:I have AquaClear HOB filters on most of my smaller -50 gallon tanks.
I pull the filter and add filter floss/polyester pillow filler to the HOB and in a couple of hours I can see an improvemnent.
IHTH
Starfish- Veteran Member
- Posts : 1202
Join date : 2013-09-08
Location : Southampton, Ontario

» Cloudy tank
» First Time with Cloudy Water?!
» first water change?
» Do you tear down or change tanks regularly?
» Water Vac and Ich
» First Time with Cloudy Water?!
» first water change?
» Do you tear down or change tanks regularly?
» Water Vac and Ich
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