High Phosphates - low Nitrates - what next?

[SycoCell]

I'm having an issue with hair algae on a few of my rocks in my 120g. The tank itself is very stable. Parameters haven't changed in many months. 1.025sg, <1 Nitrate, .010 Phosphates, 430 Calc, 10.0 dKh, 8.2-8.3 pH, 0 everything else. 10 small fish (goby, clowns, cardinals, damsels), large cleanup crew, feeding two drum rotations every other day (sometimes daily) with the occasional frozen food (weekly).

How do I remove phosphates? My ATO is from my BRS 5 stage RO/DI system which always shows 0TDS. My nitrates aren't even registering on my API kits, but only show when I use my high sensitivity Red Sea Algae control kit for PO4 and NO3. I have NoPox but don't use it because from what I understand, I need to have very slight Nitrates in the tank for the softies to be happy.

My tank itself is very clean. I do bi-weekly 35g WC's and have auto dosing through my Apex. The sandbed stays very clean. But the hair algae is on about 2-3 of my rocks in my tank (seems like low flow areas to be honest).

 

[mcgyvr]

First.. watch your overfeeding.. higher phosphate levels are usually attributed to overfeeding as most foods are high in phosphates.. So start there..
Then.. either/or/and
1-Increase water changes
2-Nopox (your softies will be fine)
3-GFO (it binds phosphate specifically and does it really well)

 

[SycoCell]

First.. watch your overfeeding.. higher phosphate levels are usually attributed to overfeeding as most foods are high in phosphates.. So start there..
Then.. either/or/and
1-Increase water changes
2-Nopox (your softies will be fine)
3-GFO (it binds phosphate specifically and does it really well)

Would NoPox be a bad idea since I don't have any real nitrates as is?

GFO was my next thought. I'd have to use a reactor, right? I can't just pour the stuff into one of my socks?

 

[mcgyvr]

Would NoPox be a bad idea since I don't have any real nitrates as is?

GFO was my next thought. I'd have to use a reactor, right? I can't just pour the stuff into one of my socks?

No.. nopox is fine.. try it for a few weeks and see how it goes if you want..

and you do not "need" a reactor for GFO but its faster working that way.. But your phosphates are pretty low anyways so a sock in a decent flow area should be ok..

Personally I'd bet you would be fine with just reducing feeding anyways and just see how that goes.. But a quick round of GFO to get it down wouldn't be bad..
However I'd also bet your hair algae really isn't a problem either (but you didn't include pictures).. Too many just overreact to a minor algae issue.. Heck I just look at a few small patches as food for my tanks inhabitants.. and they will take care of it..

 

[ReeferNoob4ever]

I too leave the patches for my inhabitants to graze on. I would be a little worried if I didn't have any algae in my tank, but also if it started spreading like fire.

 

[DivingTheWorld]

You're running less than 1 Nitrate and 0.01 Phosphate and you want to lower even further? I understand the want to reduce algae, but IMO you're low enough. I'd just look at something to eat the algae such as Turbos or a Tang or Foxface. It's possible that the hair algae is taking up some nutrients causing false readings, but if it's only on a few rocks I doubt it.

Now if it's Bryopsis and not actually hair algae, that's a different story. You need to dose meds for that.

Personally I run around 5 Nitrate (I dose) and 0.01 Phosphate. The only algae I have is some bubble algae. Any other algae is taken care of by my clean up crew before I see it.

Also, if you're serious about tracking low Phosphate, pick up a Hanna Phosphorous tester.

 

[DarkSkyForever]

Also, if you're serious about tracking low Phosphate, pick up a Hanna Phosphorous tester.

To further clarify, they refer to this one as "Phosphorus Ultra Low Range Colorimeter HI736". It measures phosphorus instead of phosphate in your water, so you'll need to convert the number it gives you using the following formula to get PO4 ppm:

(P*3.066)/100

So a reading of 6 on the ULR reader would be

(6*3.066)/1000 = 0.018396ppm PO4

 

[LuizW13]

Could you substitute the phosphate tester for the phosphorous? If the phosphorous tester is more sensitive, why don't people by that one instead of the phosphate?

 

[DivingTheWorld]

If the phosphorous tester is more sensitive, why don't people by that one instead of the phosphate?

We do.

BRS did a comparison of the two and found the results to be negligible. But my personal non-scientific experience testing the two against each other for a couple months found the Phosphorous tester to be more accurate. Anything testing under 0.03 would generally show as 0.00 on the Phosphate tester.

So I sold my Phosphate tester and I only use Phosphorus.

 

[LuizW13]

awesome, thanks for the heads up!

 

[SycoCell]

Yeah, it's definitely not taking over the tank. I'll reduce feeding a bit and see what happens. The hair is only on the rock directly below one of my powerhead while the rest of the hair is in various places behind some of my rock work down low where I'm assuming has poor flow.