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hair and staghorn algae in NPT

2025 Views 5 Replies 4 Participants Last post by  helenf
My 5 gallon NPT is now about 3 months old, and I am growing some algae!

I'm not worried about the green spot algae. I have small quantities of that in all my tanks. But I'm getting a mix of staghorn and hair algae, neither of which I've seen before. They are increasing quite quickly - obvious growth over the last couple of weeks.

I'd like to get on top of the algaes before they get on top of me, if possible. Any suggestions?

The tank is 5 gallon, heavily planted with fast growers and duckweed on top. Everything is growing well, though the anubias nana shows little growth (maybe because the snail keeps pushing it about). Some of the hygros are nearly managing emersed leaves, and everything could do with a trim.

The stock is several male endlers, an apple snail and a female betta. And some tiny caridina shrimp (actually I haven't seen the shrimp recently, and I suspect that the betta might have eaten them, though maybe they are just in the back in the plants).

The tank gets good southern daylight (I'm in Australia, so this isn't as bright as northern daylight) and a bit of sun in the mornings through an east window, maybe 30 minutes of sun in total. I turn on a 13W CF light over it for a few hours in the evening, mainly so I can view the fish, and originally to keep the duckweed growing, though I am not so concerned about the duckweed now that the other plants are getting big and the tank's nitrogen cycle seems established.

Ammonia and nitrite are always 0 now (had a bit of nitrite hanging about earlier, but this has subsided). Nitrate 5ppm, phosphate >3ppm (coming out of the soil, I think), PH 7.2, haven't measured anything else. There is very little circulation in the water, only that caused by the heater.

I would appreciate any suggestions about how to discourage the algae. I don't want to do anything that might risk the plants or fish in the process, though.
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I have a pretty similar situation in my 20 g NPT, except I do have a nice water circulation (my other two NPT tanks don’t have that green hair stuff growing so rapidly and it does get on top of me already!) and I would love to hear what people say about it.

Subscribing to this thread immediately! :D
I would say 30% water change every 3 days and then make sure to fertilize after the water change.
Another thing I learned and continue to use is a pippette with H2O2 which is hydrogen peroxide. I load up the pipette with the peroxide and squirt it on problem algae spots. When used correctly it doesn't affect the fish. I would use it before the water change.:croc::croc:
I would say 30% water change every 3 days and then make sure to fertilize after the water change.
Another thing I learned and continue to use is a pippette with H2O2 which is hydrogen peroxide. I load up the pipette with the peroxide and squirt it on problem algae spots. When used correctly it doesn't affect the fish. I would use it before the water change.:croc::croc:
Why the water change and why fertilize afterwards?

There is no excess nitrate to remove from the water, so why the water change? To remove something else? To add something else? If so, what?

This is a relatively new NPT, and the plants should be getting everything they need from the soil. The plants are growing well. Fertilizing will surely just add more nutrient to the water column where the algae can use it.

Not saying you're wrong. I don't have much experience with these things. But I need to understand why you are making these suggestions before I'll be comfortable implementing them.
I have the same problem with my NPT. I have a 6gal with 13w CF that is switched on for 8 hours a day. There is also no trace of ammonia or nitrites. I just ordered a 24w CF light to test my hypothesis that there is not enough WPG. This is causing the plants to not metabolize fast enough to out compete with the algae. Hope I'm right. :biggrin:
You could be right, but I reckon that CO2 is the limiting factor in my tank, not light.

This can be tested - if the PH changes over the day, then enough CO2 is being removed from the water as the plants photosynthesize to make a difference to the PH. When I was running the 13W over my 5 gallon tank during the daytime, the PH was varying from 7.1 to 7.6-7.8 during the course of the day. I ended up deciding that this was clearly too much light, and turning the artificial light off during the daytime. Now I only use it at night.
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