Very low nitrates, but very high phosphates

[bradv123]

Hello,
My tank (75g) has been set up for a few months now and and I've been noticing what seems to be an unusual trend with my levels.
My nitrates are very low (around 0-1) ever since I added chaeto to my fuge. My phosphates are kinda high (highest I saw in a test was 0.4). I've since started running GFO in a small reactor, and cut the light cycle on my fuge to just 6 hours a day (at night, turning on a little after dt lights go off, this was in hopes to raise the nitrates back up a little). I added GFO about a week ago and they are slowing coming down (currently around 0.2). I also have been getting some hair algae.
In the tank for fish is 2 clowns, stripped blenny, 3 firefish, 2 fighting conchs, and a handful of hermits / snails
Coral: zoas with maybe 7 polyps, gsp, a few sps (some type of montipora), a few heads of candy canes, 2 heads of duncan, and a hammer.
Does anyone have any recommendations to how to manage this? From some research I did, people seem to have the opposite problem, phosphates too low and nitrates too high. I have red sea's no-po4x but I don't want to use it since it will also remove nitrates and I don't want to bottom those out and risk a low nutrient environment and get dinos or something. Should I get some kind of liquid phosphate remover? Should I start dosing nitrate? In either case which do people recommend?
Thanks

 

[Tom Blevins]

following.

 

[Crashnt24]

You are already taking the right steps. Gfo or a liquid phosphate remover will do the same thing. I like both methods, they both have pros and cons.

Liquid:
Pros- just a couple drops in the skimmer.
Cons- the byproduct isn't completely removed by mechanical filtration, leaving this stuff forever in your tank.

GFO:
Pros- pull phosphate into media, remove media. Nothing left behind in tank.
Cons- expensive and time consuming to change media.

As for nitrates, scaling back your chaeto growth will help keep nitrates available. I recommend a LED refugium light with adjustable intensity. That way you can lower the intensity while keeping the full 12ish hour photo period. It's important for me to keep my refugium on a complete reverse light cycle to control PH swings. Reducing the photo period can reduce this benefit of a sump refugium.

Good luck!

 

[bradv123]

You are already taking the right steps. Gfo or a liquid phosphate remover will do the same thing. I like both methods, they both have pros and cons.

Liquid:
Pros- just a couple drops in the skimmer.
Cons- the byproduct isn't completely removed by mechanical filtration, leaving this stuff forever in your tank.

GFO:
Pros- pull phosphate into media, remove media. Nothing left behind in tank.
Cons- expensive and time consuming to change media.

As for nitrates, scaling back your chaeto growth will help keep nitrates available. I recommend a LED refugium light with adjustable intensity. That way you can lower the intensity while keeping the full 12ish hour photo period. It's important for me to keep my refugium on a complete reverse light cycle to control PH swings. Reducing the photo period can reduce this benefit of a sump refugium.

Good luck!

Reducing the fuge light intensity is a good idea. I didn't even think of that as an option. I don't have a way of dimming it currently, is there something I could put in front of it to reduce it until I can get a new one?

 

[Crashnt24]

Reducing the fuge light intensity is a good idea. I didn't even think of that as an option. I don't have a way of dimming it currently, is there something I could put in front of it to reduce it until I can get a new one?

Well depends on what light your using. If it's a standard screw in bulb like a CFL, they have dimmable bulbs and dimmer switches you can install. I don't think a dimmer would work on anything else that has a ballast or internal board(led).

 

[bradv123]

Well depends on what light your using. If it's a standard screw in bulb like a CFL, they have dimmable bulbs and dimmer switches you can install. I don't think a dimmer would work on anything else that has a ballast or internal board(led).

I meant more along the lines of is there a material I can put between the light and fuge that will block some of the light? Im using a full spectrum led outdoor flood light. Maybe a frosted acrylic? or something like that? Also do you not recommend I dose nitrates? Just reduce chaeto growth?

 

[bradv123]

Would it be worth trying something like red sea no3-po4-X? I already have this on hand so I was considering using it to get phosphates down faster so I can remove the hair algae

 

[Crashnt24]

I meant more along the lines of is there a material I can put between the light and fuge that will block some of the light? Im using a full spectrum led outdoor flood light. Maybe a frosted acrylic? or something like that? Also do you not recommend I dose nitrates? Just reduce chaeto growth?

You could use a clear sheet of acrylic. You'd be surprised at how much light a 1/4" of acrylic blocks. I would be weary of anything frosted as it might block too much. You could add additional sheets of acrylic to stack as needed.

I'm not a fan of dosing unless as a last resort. The reason being that you're not dosing JUST nitrate, your dosing sodium as well. Granted excess sodium isn't as dangerous as something like iodine. Regardless, it can build up over time and put things out of balance.

 

[Ippyroy]

Chaeto and most algaes use NO3 at a much faster rate then PO4. I run my fuge light for 45 on and then 30 off all night long. This helps to keep my PH more in balance. I'd stick with the GFO personally and just keep an eye on the PO4 levels, they can bottom out quickly.

 

[bradv123]

Thank you both @Crashnt24 and @Ippyroy for you suggestions. I think ill add some acrylic between the chaeto and light, and ill just keep running GFO. Will GFO remove ALL phosphate? or will it leave any? I really don't want to deal with dinos so im a bit afraid of a very low nutrient environment. I added about 1.25 cups of GFO (non hc) for a water volume of around 85g is this enough or should I be running more? Also would it be better in a media bag or a small reactor?

 

[Ippyroy]

Thank you both @Crashnt24 and @Ippyroy for you suggestions. I think ill add some acrylic between the chaeto and light, and ill just keep running GFO. Will GFO remove ALL phosphate? or will it leave any? I really don't want to deal with dinos so im a bit afraid of a very low nutrient environment. I added about 1.25 cups of GFO (non hc) for a water volume of around 85g is this enough or should I be running more? Also would it be better in a media bag or a small reactor?

Media bags are nice for ease of use. Just test the PO4 daily and remove bag or turn off reactor when levels are where you want them. GFO is strip out all PO4. I'd run til you get to about .05 or so and test daily after that. You might need to run it constantly or maybe just a week a month. Every tank is different.

 

[bradv123]

Media bags are nice for ease of use. Just test the PO4 daily and remove bag or turn off reactor when levels are where you want them. GFO is strip out all PO4. I'd run til you get to about .05 or so and test daily after that. You might need to run it constantly or maybe just a week a month. Every tank is different.

Okay, thanks for the suggestions. Ill just keep an eye on it. I have some rewards points for BRS, if only the ULR phosphate hanna checker was in stock since they're on sale today. Oh well

 

[excell007]

I meant more along the lines of is there a material I can put between the light and fuge that will block some of the light? Im using a full spectrum led outdoor flood light. Maybe a frosted acrylic? or something like that? Also do you not recommend I dose nitrates? Just reduce chaeto growth?

make the height of the light adjustable, this is the same as reducing intensity reaching the chaeto. As for dosing nitrate, just remove some of the chaeto.

 

[Ippyroy]

Okay, thanks for the suggestions. Ill just keep an eye on it. I have some rewards points for BRS, if only the ULR phosphate hanna checker was in stock since they're on sale today. Oh well

The Hanna is nice, but not as great as the Alk checker. But 15% off is crazy. I use the salinity checker and love it. I hated my refractometer. Their refacto juice was off and my tank got way off. Took a month to correct it.