Who Gives A Fish Forums

My aquarium has been cloudy for days, even after multiple water changes. I've tested the water, 0 ammonia, 0 nitrite, 5 nitrate. Running a Fluval 307 on a 40 gallon with sand substrate. Any ideas what's causing this?

Cloudiness can be bacterial blooms or fine particles from the substrate. How often do you clean the filter? Sand can kick up easily if disturbed. Try adding filter floss to catch the fines.

Yo, same thing happened to me last month. Turns out my sand was the culprit. Gotta rinse it way more than you think, or it'll mess with your water clarity for ages.

starboy wrote: ↑Tue Jul 15, 2025 1:26 am Yo, same thing happened to me last month. Turns out my sand was the culprit. Gotta rinse it way more than you think, or it'll mess with your water clarity for ages.

Agreed. Also, check if your filter flow is too strong. High flow can stir up sand particles.

Have you added anything new to the tank recently? Sometimes decorations or plants can introduce dust or debris. I had a similar issue after adding driftwood.

Dude, bacterial blooms are the worst. They usually chill out on their own if you cut back on feeding and keep up with water changes. Patience is key, my friend.

Cloudiness often resolves within a week if parameters are stable. Monitor your tank's behavior and avoid over-cleaning, as it can prolong the issue.

I had this problem too. My tank cleared up after I added some Seachem Clarity. Maybe give that a try?

Thanks for the suggestions, everyone. I'll try adding filter floss and reducing the flow. Hopefully it clears up soon.

Rivora9 wrote: ↑Tue Jul 15, 2025 5:02 am Thanks for the suggestions, everyone. I'll try adding filter floss and reducing the flow. Hopefully it clears up soon.

Let us know how it goes. Sometimes these things just need time.