Cloudy water after putting algae plants

[Iamable2099]

I placed a green algae plant and a red algae plant that lost all color of red ( may have died during quarantine) now my tank is extremely cloudy. I removed the plants. Phosphate levels are lowering. Is this good or bad?

 

[JTP424]

Can you confirm what type of algae plant you added?
Has your tank been fully cycled?

 

[UncommonSense]

If I had to guess, this is a bacteria bloom!

More importantly… is this tank sitting full of water with each side dangling around six inches off the stand??

 

[Subsea]

If I had to guess, this is a bacteria bloom!

More importantly… is this tank sitting full of water with each side dangling around six inches off the stand??

@lamable2099
YOUR 20G TANK IS NOT SUPPORTED PROPERLY.

After you fix your tank stand, you need to cycle your tank with live rock to deal with insufficient biofiltration. Bacteria in a bottle are insufficient for reef biome.

Also, I read your Master Kit thread:
“Hello, 8 weeks in with 20 gallon reef tank. These are my parameters Phosphate are at .50 ppm Nitrate are at o ppm And it took 33 drops of the API master reef tank tester Calcium. Which is above the chart. I recently purchased anemones, electric eye scallop, and Duncan’s. They all died in...”

• Iamable2099
• Thread
• Jan 5, 2026
• Replies: 23
• Forum: Reef Aquarium Discussion

Even with a mature tank, flame scallops are very sensitive. I use flame scallops as my canary in a coal mine.

With 55 years of reefing experience, I have been unable to sustainably keep electric eye flame scallops.

YOUR TANK IS NOT CYCLED.

 

[Iamable2099]

Can you confirm what type of algae plant you added?
Has your tank been fully cycled?

Live Saltwater Gracilaria Pom Pom Red Macro Algae 1 Inch lost all color during quarantine thought I could revive it by adding it to my tank​

And
Sea lettuce ulva

 

[Iamable2099]

Can you confirm what type of algae plant you added?
Has your tank been fully cycled?

Live Saltwater Gracilaria Pom Pom Red Macro Algae 1 Inch lost all color during quarantine thought I could revive it by adding it to my tank​

And

@lamable2099
YOUR 20G TANK IS NOT SUPPORTED PROPERLY.

After you fix your tank stand, you need to cycle your tank with live rock to deal with insufficient biofiltration. Bacteria in a bottle are insufficient for reef biome.

Also, I read your Master Kit thread:
“Hello, 8 weeks in with 20 gallon reef tank. These are my parameters Phosphate are at .50 ppm Nitrate are at o ppm And it took 33 drops of the API master reef tank tester Calcium. Which is above the chart. I recently purchased anemones, electric eye scallop, and Duncan’s. They all died in...”

• Iamable2099
• Thread
• Jan 5, 2026
• Replies: 23
• Forum: Reef Aquarium Discussion

Even with a mature tank, flame scallops are very sensitive. I use flame scallops as my canary in a coal mine.

With 55 years of reefing experience, I have been unable to sustainably keep electric eye flame scallops.

YOUR TANK IS NOT CYCLED.

tank has been going for 3 months now… added bacteria with aquavittro seed then I have been feeding a few hermit crabs and ghost feeding for 10 weeks plus.

The foggy appears more likely came from sea lettuce.


I’m pretty sure my tank is cycled by now my phosphate levels are almost at zero.

 

[UncommonSense]

Live Saltwater Gracilaria Pom Pom Red Macro Algae 1 Inch lost all color during quarantine thought I could revive it by adding it to my tank​

And

tank has been going for 3 months now… added bacteria with aquavittro seed then I have been feeding a few hermit crabs and ghost feeding for 10 weeks plus.

The foggy appears more likely came from sea lettuce.


I’m pretty sure my tank is cycled by now my phosphate levels are almost at zero.

The more important factor here is the tank stand… this aquarium is currently peeling apart at the seams…

 

[JTP424]

Phosphates at zero is going to kill your macros. IT'S THEIR FOOD!!

 

[Fish Fan]

tank has been going for 3 months now… added bacteria with aquavittro seed then I have been feeding a few hermit crabs and ghost feeding for 10 weeks plus.

The foggy appears more likely came from sea lettuce.


I’m pretty sure my tank is cycled by now my phosphate levels are almost at zero.

I think we need to pump the brakes here just a bit

Beyond your initial question, there is a very real concern that your tank is not being fully supported by whatever you have under it acting as a stand. The sides of the tank are hanging completely off the stand, which is not a good setup at all.

Do you have or can you make a more supportive stand for your tank? I think that's the most pressing problem so far

Here's a link to a very simple, cheap and strong DIY stand plan made from 2x4's:

Basic DIY Stand Calculator

This is a repost of my previous calculations. Again, this is not my design but has become connected with my name over the years. The basic principle of the design is two box frames connected by four legs. The upper one supports the tank and transfers the load to the legs. The legs are made of...

www.reef2reef.com

Then, to me - and I could just be looking at it wrong - but that green plant looks like something from freshwater, it doesn't look like a saltwater macro algae to me

The "foggy" is caused by bacteria, which could be in response to the macro algae dying, but could also be from the bacteria you've added or other sources.

We would need a little more information on how you cycled your tank, when did you add the bacteria, and did you add anything for ammonia? Did you test for ammonia during the cycle? What are you using for test kits?

To be clear, phosphate concentration has nothing to do with nitrogen cycling a tank, you need to check for ammonia and then nitrate. And, as mentioned you do not want zero phosphate, that could well be what killed the macro algae.

I hope this helps; good luck!

 

[BryanM]

EVen at only 20 gallons, that salt water is going to weigh around 170 pounds.

That much of the tank unsupported is almost certainly not sustainable.

 

[UncommonSense]

EVen at only 20 gallons, that salt water is going to weigh around 170 pounds.

That much of the tank unsupported is almost certainly not sustainable.

Precisely!

Even some of the sketchier professional glass tank installs I’ve seen at least support pretty much the full long spans of the tank!

An LFS I checked out while on vacation as an example:

 

[W31Olds]

I think we need to pump the brakes here just a bit

Beyond your initial question, there is a very real concern that your tank is not being fully supported by whatever you have under it acting as a stand. The sides of the tank are hanging completely off the stand, which is not a good setup at all.

Do you have or can you make a more supportive stand for your tank? I think that's the most pressing problem so far

Here's a link to a very simple, cheap and strong DIY stand plan made from 2x4's:

Basic DIY Stand Calculator

This is a repost of my previous calculations. Again, this is not my design but has become connected with my name over the years. The basic principle of the design is two box frames connected by four legs. The upper one supports the tank and transfers the load to the legs. The legs are made of...

www.reef2reef.com

Then, to me - and I could just be looking at it wrong - but that green plant looks like something from freshwater, it doesn't look like a saltwater macro algae to me

The "foggy" is caused by bacteria, which could be in response to the macro algae dying, but could also be from the bacteria you've added or other sources.

We would need a little more information on how you cycled your tank, when did you add the bacteria, and did you add anything for ammonia? Did you test for ammonia during the cycle? What are you using for test kits?

To be clear, phosphate concentration has nothing to do with nitrogen cycling a tank, you need to check for ammonia and then nitrate. And, as mentioned you do not want zero phosphate, that could well be what killed the macro algae.

I hope this helps; good luck!

I did a double take when I noticed that plant in the back.

 

[Dom]

The way you have that tank perched on that trunk without support is a very bad idea.

First step, get that tank on a proper stand.

 

[W31Olds]

Lamable, I would go out and pick up some cinder blocks to support each on the 4 corners and use some pieces of wood and shims to make up the gap.

 

[Iamable2099]

The more important factor here is the tank stand… this aquarium is currently peeling apart at the seams…

Yes I have addressed this concern in another post.

I’m seeking help with water chemistry.

This tank has been up and running for nearly 3 months.

I used aqua vitro seed it’s a benéfical bacteria that you add in a span of 7 days. That happened 2 months ago.

The water was looking prestigious prior to added the dead algae plants. Both the plants are for salt water.


I performed a water change (25%)
And I noticed today the water is extremely murky. Im going to change the filter as my next step.


I instantly noticed with reef tank persons, everyone has a strong opinion but one person says nitrates don’t matter, then phosphate needs to be at zero simultaneously while another says phosphates are necessary. It’s a big back n forth mental exhaustion.

I will secure my tank but again that wasn’t the purpose of this post. I have another post showing extreme concern for the statics of the tank.

 

[W31Olds]

lamable, you tank is too new to be adding inverts and expecting success. Flame Scallops are cool (I had one many years ago) but are expert only and I would wager you would be hard pressed to find anyone on this Forum that has had success keeping them. Check your ammonia and nitrate levels. You can change the filter but more than likely it is a Bacterial Bloom that may have been caused by the dead organic matter in your new tank. Do you have anything live in it right now?

 

[Iamable2099]

I do have a few hermit crabs day have been there since day 1. Will the bloom settle out on its own?

 

[W31Olds]

I would imagine so.

 

[kizzy89]

I do have a few hermit crabs day have been there since day 1. Will the bloom settle out on its own?

The bloom will settle, it might take a couple days to a week or two depending on water changes. Ive had a couple happen. The plant in the back of the tank, is it a fake one or if real what is it? It looks like a freshwater plant and if so it could be a cause of the bloom. I accidentally added freshwater additives to a saltwater and instant bloom. Took a week to clear up. If you have other questions feel free to ask.