I Don't Understand... Algae Bloom

jason181

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HI all, I'm new here and having an issue with my 37g aquarium. About 2 weeks ago, I did a 25% water change and vacuumed my gravel. I had a massive algae bloom 2 days later. I asked my local fish store and they said I needed to do another 75% change immediatly, so I did. No change. What should I do? The water is really cloudy with a dark green tint to it. Do I need to do a regular 10% change, leave it alone? Add algae control?
 

Floundering_Around

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Hi, welcome to fishlore and the hobby! First things first, is your tank fully cycled and how long has it been set up? What are your water parameters? Nitrogen and phosphate are usually the culprits when it comes to algae blooms in tanks. If you don't have your own test kit, you can take it to your local fish store (LFS) and they'll test the water for free.
How long do you have the lights on in your tank and ware there any plants in there? Live plants will compete with algae for nitrogen, phosphorus, and other elements in the water. If you have elevated levels in your tank with no plants, you'll end up with algae thriving.
Another things, how much do you feed the tank? Too much uneaten food and waste will lead to a build-up of nitrogen, etc. Increasing your water change schedule will help to remove the excess nutrients.
To answer your question, I would say to continue doing water changes, only about 15-20% a day until the tank clears up
 

TexasDomer

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Can you list exact water parameters for pH, temp, ammonia, nitrites, and nitrates please? Telling us they're normal isn't helpful, as there are different definitions of "normal."

None of your plants will kill algae, though all are supposed to help outcompete it.

Can you answer the questions about lighting? How long do you leave your light on? What kind of light is it? Does the tank get any sunlight?

You have stocking issues if you'd like to discuss them.
 

Floundering_Around

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You have a few stocking issues to address when you get a chance:
-the cory cats should be kept in a group of six or more
-the black skirt tetras should also be kept in groups of six or more

In all my years of fish keeping, I've never heard of a plan that kills algae. Plants may deprive algae of nutrients if there's enough of them though.

When you test the water, do you use strips of drops? The strips are pretty **** honestly in comparison. They'll do for a quick test of your water but you shouldn't rely on them for accurate results
 
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jason181

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TexasDomer said:
Can you list exact water parameters for pH, temp, ammonia, nitrites, and nitrates please? Telling us they're normal isn't helpful, as there are different definitions of "normal."

None of your plants will kill algae, though all are supposed to help outcompete it.

Can you answer the questions about lighting? How long do you leave your light on? What kind of light is it? Does the tank get any sunlight?

You have stocking issues if you'd like to discuss them.
Gh 30, pH 7, kH 40, no2 0, no3 20. I have led lights that are on for 8-10hrs daily. I don't overfeed them as there is never any food that even reaches the middle of the tank.

Right now my main concern is the water. I know I have stocking issues, but I think I have a pretty full tank considering my tetras are the oldest and they are about 1.5 inches. And the same with the sharks.
 

TexasDomer

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Sounds like you're testing with strips. Any way you can get a liquid test? They're more accurate, they're cheaper per test, and they test for ammonia, which is the parameter of interest right now. In the mean time, can you take some water to your LFS to get it tested for ammonia?

How often do you normally do water changes, and how much do you change (i.e. what's your normal schedule, not including what you've done because of the LFS's advice)?

I would decrease your lighting to 6 hours for now.

Your stocking issues will become a big deal though - the sharks will kill each other, and they may start killing other fish as well. If they're only 1.5", they're nowhere near full grown, and these fish get more aggressive as they age.
 
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jason181

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TexasDomer said:
Sounds like you're testing with strips. Any way you can get a liquid test? They're more accurate, they're cheaper per test, and they test for ammonia, which is the parameter of interest right now. In the mean time, can you take some water to your LFS to get it tested for ammonia?

How often do you normally do water changes, and how much do you change (i.e. what's your normal schedule, not including what you've done because of the LFS's advice)?

I would decrease your lighting to 6 hours for now.
My first water change was 25% about 2 weeks ago. The algae was the result. And then my LFS said I should do a 75% after the algae first appeared. I'll get the other test and take a sample on this coming Friday.
 

Floundering_Around

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your nitrate is a bit high. I would try to get that down to below 10ppm, with 0-5 being ideal. COntinue with water changes and lower your lighting schedule.
What types of plants do you have? Slow growing plants, like anubias and moss, don't take up as many nutrients compared to fast-growing plants

jason181 said:
My first water change was 25% about 2 weeks ago. The algae was the result. And then my LFS said I should do a 75% after the algae first appeared. I'll get the other test and take a sample on this coming Friday.
Hold on, your first water change was two weeks ago? I'm assuming the tank is new but is it fully cycled?
 
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jason181

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Floundering_Around said:
Hold on, your first water change was two weeks ago? I'm assuming the tank is new but is it fully cycled?
Yes, fully cycled. I got the tank at the beginning of March. I had no issues until my first water change. Starting to think I should've never done it. Lol
 

TexasDomer

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jason181 said:
My first water change was 25% about 2 weeks ago. The algae was the result. And then my LFS said I should do a 75% after the algae first appeared. I'll get the other test and take a sample on this coming Friday.
Your first water change in 3 months?? Your poor fish. There's your problem. You should be doing at least weekly water changes, and I'd recommend more often for now since you're having issues.

The algae isn't because of the water change per say, but likely because of the lighting that's long and the lack of water changes in the beginning. You should definitely be doing more frequent water changes. The algae issue will improve with a routine water change schedule.

So to start with:
-50% water changes at least weekly, but for now I'd do it a few times a week since you didn't do any for the first few months
-decrease lighting to 6 hours
-make sure tank isn't getting any direct sunlight


How do you know your tank is fully cycled if you don't have a reading for ammonia?
 
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jason181

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TexasDomer said:
Sounds like you're testing with strips. Any way you can get a liquid test? They're more accurate, they're cheaper per test, and they test for ammonia, which is the parameter of interest right now. In the mean time, can you take some water to your LFS to get it tested for ammonia?

How often do you normally do water changes, and how much do you change (i.e. what's your normal schedule, not including what you've done because of the LFS's advice)?

I would decrease your lighting to 6 hours for now.

Your stocking issues will become a big deal though - the sharks will kill each other, and they may start killing other fish as well. If they're only 1.5", they're nowhere near full grown, and these fish get more aggressive as they age.
Exactly why I don't really want to add anymore fish right now. I plan on getting another tank in a few months. Maybe 55g.
 

TexasDomer

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I would still strongly consider rehoming the sharks now, before they kill something. You can get one after you get your 55 gal tank.
 

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