Cloudy Aquarium

  1. qquake2k Initiate Member

    This is my 16 gallon bowfront. I'm running a Fluval 206 canister filter on it. It has been established for several years now, and is usually crystal clear. About two weeks ago it started gradually getting cloudy. Last weekend, I did a partial water change, and rinsed out the filter media in the siphoned tank water. There was no noticeable improvement, so two days later I replaced two of the four course foam blocks, replaced the polishing pad, and added a bag of carbon. I also added a small HOB filter I had just for fun. Now, a week later, it appears worse if anything.

    I tested the water this morning, and the only thing I see is the nitrates are high. (Yes, I know stick tests are notoriously unreliable, and I do have an API test kit. I did this just for a quick look. I don't need a lecture on test methods.) Any suggestions for my next steps? I don't think it's overstocked. I have a pleco, two cories, two neon tetras, and four tiger barbs. No fish have died recently.

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  2. Dragones5150918 Well Known Member Member

    What color is the cloudiness? It looks white to me, which makes me think a bacterial bloom. if it's green, it's an algy bloom.

    My hypothesis is if it's white, something changed in your tap water in the past few weeks, since its been established for years. I would start there. It can take a few weeks for the cloudiness to go away. You will see it lighten up, then one morning you will wake up and bam, clear tank.

    If it's green, because of the high nitrates, you were able to get an algy bloom. I would do a large water change to get the nitrate down, and cut down how long your light is on. If you have live plants, 3 hours on, 2 hours off, and 2 hours on. Or just turn off the light at the 5 hour mark. If no live plants are in the tank, just leave the lights off for a couple of days and moniter your nitrate. Frequent water changes to remove nitrate.

  3. qquake2k Initiate Member

    I think it's white. I'll try a 50% water change, and get some live plants. What kind of plants would be good? It's sand substrate.
  4. Dragones5150918 Well Known Member Member

    Water change won't help a bacterial boom. Just let it cycle out.

  5. qquake2k Initiate Member

    But water changes should help lower the nitrates, which are high.
  6. Dragones5150918 Well Known Member Member

    That's true. Forgot you had fish in there.
  7. qquake2k Initiate Member

    It was a lot worse this morning. I think it's definitely an algal bloom.

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  8. Dragones5150918 Well Known Member Member

    Yeah that's green. You can keep your light off for a day, it will help cut it down. Your plants can handle a couple of days with out lights. Another solution is a black out. Keep the lights off and cover the tank to cut out any room light for 48 hours.

    Also cut down the amount you feed your fish.
  9. CindiL Fishlore Legend Member

    Hi, the high nitrates will feed the bloom. First thing I would do is get your nitrates down to below 20. What is your water change routine like? How often? How much?

    Your KH looks quite low right now, what is the KH of your tap? Not doing enough water changes will also lower the carbonates by the acidity of the nitrogen cycle itself, this can lead to a ph crash.

    I have a feeling if you get your nitrates under control, other parameters should improve.