p=0 and N=0, why have I algae?

[luison]

Hi everybody. This is my first thread in this great forum. First, Sorry for my english, I'm from Spain and my english still isnt very good. In the title I say that I have algae in my tank. But... how it's possible if my level nutrients are 0 (Salifert's test) N=0 and P=0. Im crazy and desesperate. The algae are hair brown and the rest of the paramenters are ok.

Thank's in advance. LuiSoN

[mcoomer]

What kind of filtration are you running in your system? Is there any part of your filter that could consume the nitrates while still causing the algae growth that you're seeing? What types of inhabitants do you have, how much are you feeding them, and what are your feeding them? What kind of water change schedule do you keep and are you using RO/DI water? Give us some more details and you'll get better replies to your question.

Welcome to the board,
Mike

[Nanook]

To Reef Central

Even though your levels are at zero, you can still have N&P in the water column and the algae are taking them in. I would suggest trying to remove the hair algae manually and making sure your source water is good. Are you using RODI water?

I use a Hanna meter for phosphates and Lamotte for Nitrates. Perhaps carbon and GFO might help too if your source water is good. Consider feeding habits as well.

[Froggy]

1st off, Welcome to Reef Central and your English is fine as well

Salifert does not really test well in the very low range for Phosphate. Chances are there is still a measurable amount that would show up on a low range test like a Hanna meter etc.

Some algae also seem tho thrive in very low levels also. Any chance of posting a picture of the algae to try and possitively identify it ?

[luison]

Originally Posted by mcoomer

What kind of filtration are you running in your system? Is there any part of your filter that could consume the nitrates while still causing the algae growth that you're seeing? What types of inhabitants do you have, how much are you feeding them, and what are your feeding them? What kind of water change schedule do you keep and are you using RO/DI water? Give us some more details and you'll get better replies to your question.

Welcome to the board,
Mike

Hi Mcoomer, i have a 240l tank with 30 kg of live rock and dsb. Im feeding 1 per day. I use water RODI system and I change water 10% per 15 days. I only have 8 fishes 1 Blue tang, 2 occellaris, 1 yellow tang, 2 aruanus damsels, 1 butterfly, 1 cromis.

Thanks in advance.

[Nanook]

Is your RODI water reading 0 TDS? Is your liverock fresh, or did it come from someone else's tank? Sometimes older liverock from a previous owner will leech phosphate and lead to algae.

Might want to check with low range test kits as mentioned, if the numbers are elevated, then running some GFO (granular ferric oxide) will help bring phosphate down.

[luison]

Originally Posted by Froggy

1st off, Welcome to Reef Central and your English is fine as well

Salifert does not really test well in the very low range for Phosphate. Chances are there is still a measurable amount that would show up on a low range test like a Hanna meter etc.

Some algae also seem tho thrive in very low levels also. Any chance of posting a picture of the algae to try and possitively identify it ?

Hi Froggy, the next image show the kind of algae.

[mcoomer]

As mentioned above, try manually removing as much as you can and maybe step up your water changes for the near term to remove more of the nutrients in your water that are feeding the algae. I'd also recommend cutting back on your lighting period for the near term, or going completely dark for several days. By the way, is the algae a new problem or has it always been present and recently gotten worse?

Mike

[luison]

Originally Posted by mcoomer

As mentioned above, try manually removing as much as you can and maybe step up your water changes for the near term to remove more of the nutrients in your water that are feeding the algae. I'd also recommend cutting back on your lighting period for the near term, or going completely dark for several days. By the way, is the algae a new problem or has it always been present and recently gotten worse?

Mike

Hi, the problem isnt new I've 4 month with this algae. Im try everything. I dont see the solution.

[Mentat]

Originally Posted by luison

p=0 and N=0, why have I algae?

Test kits provide "net" readings concurrent with all biological process in tank. You could have nitrates and phosphates that the algae are very efficiently using to grow.

[PTubman]

just because they test zero does not mean that you are not producing nitrates or phosphates. Your algae could be consuming the nutrients as soon as they are produced, therefore non traceable amounts in the water column but growth for algae

[Fish2reef]

It could be stored on the rocks leaching out and consumed by the algae before reaching the water column. In that case time will take care of the problem as long as you do not contribute to the problem.

[Nanook]

Algae needs fuel to grow...so, it is either in the water column: overfeeding, too many fish; or, it is in the liverock and leeching out. Algae also needs light to grow, so, cutting the lights out will temporarily solve the algae, but you will still need to figure out what caused it in the first place.

[luison]

Originally Posted by PTubman

just because they test zero does not mean that you are not producing nitrates or phosphates. Your algae could be consuming the nutrients as soon as they are produced, therefore non traceable amounts in the water column but growth for algae

Hi PTubman, Im rigth with you, but what is the cause? Maybe much fishes, a lot of feeding,... Im try all, for example: One day I feed the fishes and three not during one month and all equal. Im not to do.

Thanks.

[Nanook]

How old is the rock, did you get it new or from another aquarium?

[luison]

Originally Posted by Nanook

How old is the rock, did you get it new or from another aquarium?

Hi, the rock is 4 years old.