Brand New Aquarium (Very Cloudy) - Bacteria Bloom Already? 24 hours

Hey everyone,

Just got my new tank up and running. It's been about 24 hours, and the water is still super cloudy. Kind of looks like a bacteria bloom, but it feels too soon for that, considering it's a fresh setup. I threw in 1/3 water from my old tank to kickstart the good bacteria, but now I'm second-guessing if that was a good move.
I used Seachem Flourite Black for the substrate, first time trying it. Noticed it was a bit messier than the Tropica Aquasoil I've used in the past. Gave it a good rinse before adding it to the tank.

When I set up my 50-gallon tank a few months ago, the water cleared up almost instantly. Now, not so much.

Any guesses if it's a bacteria bloom or maybe my filter isn't cutting it? I'm running a cheap nano tank filter from Amazon with an appropriate GPH flow rate.

What should I do:
1.) Leave it and hope for the best?
2.) Grab some water clarity chemical?
3.) Opt for a water change?

Thanks a bunch in advance!

This is common and usually caused by dust in the substrate.

Wipe the glass down with a clean sponge. If it's still cloudy then drain and refill the tank with dechlorinated water.

Look up new tank syndrome. Sounds like that to me.

Bacterial blooms are common in new tanks. These are not the same as the bacteria we want to grow. Bloom bacteria feed on carbon based food; filter bacteria feed on nitrogen based food. Bloom bacteria live floating in the water; filter bacteria live in the biofilm on surfaces. Bloom bacteria multiply quickly; filter bacteria multiply slowly.


Water providers add chlorine or chloramine to the water to kill bacteria. It kills most of them but not all. There is organic (carbon based) matter in tap water, and in everything plastic in a tank. We set up a tank and put in water which has water conditioner added. That removes the chlorine/chloramine and now the bacteria in the water are not inhibited. The bloom bacteria start feeding on the organic matter and multiply and multiply. Because there are so many of them so quickly and they live in the water we see them as cloudiness. The good news is they die off once they've eaten all their food and the water clears. The time this takes varies from tank to tank so anything from several days to a couple of weeks.



And of course it could be dust from the substrate which will settle to the bottom and the tank will clear. Some extra filter floss in the filter helps clear the dust, though it won't affect a bacterial bloom.

If the cloudiness was present when you filled the tank and didn't appear with time. It's super fine dust.

Some substrate makes dust so fine, it passes trough the filter media like nothing was there. The cloud can remain for weeks. Aquarium filters are not mechanically sound to remove such small particles.

Drain the tank as much as possible and fill it back with treated water, Use a siphon and a dish plate to fill the tank without disturbing the substrate as much as possible. Thoroughly rinse the filter media and flush the enclosure too.

Don't wipe the glasses if it's sand dust, it will scratch your tank. It's even worse with acrylic tanks.

I wouldn't be worried about it. Give it time and it will pass. You're just at the beginning of your tank cycle.