Help With Green Water....

[KAISER]

Hey everyone,

For the last couple of weeks my tank has been cloudy. At first I thought it was a bac bloom after I had cleaned the substrate of algae and cleaned part of the filter media. The water never really had a colour to it, but in the last week it has been getting greener. Looking long ways down the tank, you can barely see half way!

Heres some stats...

Tank size: 125L
Age: Approx 3 months
Plants: Vallis, and some kind of grass? (no ferts added since start of bloom)
Stocking: 4 Platy, 20 ish Platy fry (some are getting quite big), 2 Julii Cory, 1 Bulldog Plec (small).

ph 6.8
ammonia 0.50 ppm
nitrite 0 ppm
nitrate 5 - 10 ppm

I carried out a 50% water change and grav vac and originally planned to black out the tank for the next 4 days, until I seen the ammonia spike. So what should I do now?

Thanks

 

[PDSimon]

You have 0.5 ammonia? That won't be doing your fish any good at all, and if that goes on could easily cause permanent damage. It also helps algae grow a lot...

Ferts will help the plants grow and out compete the algae so I would go back to dosing them. I think dosing liquid carbon would help fight the algae although i'm not sure of this...

you might want to consider turning how long the lights are on for. how long are they on for?

waterchanges are in order to remove the ammonia

 

[RadaR]

As stated by PDSimon, having an ammonia reading on a test kit is bad for fish. Undoubtly it's causing your green water.
Even ammonia levels that are too small to come up on a test kit (so small that it doesn't harm fish) can cause algae.
Keep doing water changes to reduce the ammonia and algae spores in the tank.
Once the ammonia reading is gone then just make the plants get everything they need in the way of micro nutrients, macro nutrients, CO2 and flow.

 

[KAISER]

You have 0.5 ammonia? That won't be doing your fish any good at all, and if that goes on could easily cause permanent damage. It also helps algae grow a lot...

Ferts will help the plants grow and out compete the algae so I would go back to dosing them. I think dosing liquid carbon would help fight the algae although i'm not sure of this...

you might want to consider turning how long the lights are on for. how long are they on for?

waterchanges are in order to remove the ammonia

Yep, thats what I was thinking. The lights have been reduced down to four or five hours a day and for the last two haven't been on at all.

As stated by PDSimon, having an ammonia reading on a test kit is bad for fish. Undoubtly it's causing your green water.
Even ammonia levels that are too small to come up on a test kit (so small that it doesn't harm fish) can cause algae.
Keep doing water changes to reduce the ammonia and algae spores in the tank.
Once the ammonia reading is gone then just make the plants get everything they need in the way of micro nutrients, macro nutrients, CO2 and flow.

Thanks, will deal with the ammonia first, dose the ferts and report back later

 

[mtv8dmarine]

Well how long were the lights on previously? You may not need to back the time down to 4 - 5 hours. If you previously had them on for say 12 hours, simply turning them off after 8 would be a big difference as you would reduce the light time by 33%.

I do agree that the first culprit is the ammonia and of course water changes would help reduce it. How big are the platy fry? That's a lot of fish in total. Is it possible that the beneficial bacteria is having a hard time keeping up with all of the waste and food which is leading to the rise in ammonia?

 

[anshuman]

simply stop dosing the ferts for 3-5 days and keep lights on only for a HOUR, thats it, for 5 days. and do the 50% water change every 2 days, the green algae water will vanish just like that, after that make sure your tank has no Ammonia spikes , even .5 is bad.

 

[mtv8dmarine]

Wow, that's good info. I didn't realize treatment was that aggressive. But hey, if it gets it done in 5 days who can argue?

 

[RadaR]

To quote James from his algae guide in my sig

Large water changes do not seem to always help. If there is an imbalance in nutrients then fixing it will sometimes make it go away by itself after a while. A three day blackout followed by a large water change will hit it hard and sometimes may clear it. A UV steriliser/clarifier or diatom filter will clear it up very quickly and is often the only way to clear it.
A new method is to use freshly cut 1-2 year old willow branches about 0.5-1cm in width. Place these in your tank vertically so they go from the substrate to a few centimetres above the water's surface. After a few days they will start to grow roots and the green water should start to clear. When cleared remove the branches from the water.
Don't confuse this with a bacterial bloom which gives the water a white haze.

 

[KAISER]

Sorry, I didn't make a good job explaining the lighting times. The lights were being run for 7-8 hours a day up until a week and a half ago, when I first suspected this wasn't a bac bloom. They were then reduced to 3-4 hours a day for the following week and in the last few days, I haven't had the lights on at all.

As for the fry causing the spike, I had the exact same thought. The larger ones are maybe one cm in length. I wondered if the fry could be growing faster than the A-bacs can handle?

The fert I am using is called "plantamin" by "Tetra-plant". I only dose the tank once a week as per the instructions. (Actually, the instuctions say to dose only once a month, so I divided the dose by four and do it once a week.) So is the concensus I start dosing the ferts again?

 

[PDSimon]

when you have fry you often do small waterchanges everyday to help with the overflow.


I'm pretty sure it would be best to start dosing ferts, double check with that link for james algae guide above ^

 

[KAISER]

Thanks, one last question, for now at least...

The lights, leave them off or give the plants a few hours a day until the ammonia is gone?

 

[PDSimon]

Probably 3-4 hours but not entirely sure

 

[aaronnorth]

The way I always advise is:

do a 50-80% water change to remove most of the spores.
Cover the tank up with blankets/ bin liners for 3 days so no light can enter, and turn the aquarium lighting off, aswell as any CO2 & nutrient dosing. Dont feed the fish either.
do another 50-80% water change to remove the dead spores.

This pretty much clears it every time, if it returns, then it is usually because there is still something to trigger it (like NH3).

Thanks, Aaron