NO3 = 0 phosphate= 1.36

scoopsthedog · Feb 25, 2017

So my tank overall is doing well but I started testing phosphate for the first time today and got a very big reading. Other stats are below. Here is tank:

50G w/16G sump
Protein skimmer
Chateo Refugium
Carbon in a bag
Bacto balls
Sock

2 Clowns
Midas Blenny
LPS / Softies and Zoa
2 skunk cleaners
Peppermint
Fire shrimp
3 sexy shrimp
CUC

Coral seem fine. Zoas sprouting new heads. Very little / no nuisance algae.

I have been over feeding using selcon a bit and increased Reef roids based on having consistent 0 nitrate now for 3 weeks. I did a 15% water change and am considering GFO reactor. Any thoughts?

scoopsthedog · Feb 26, 2017

Randy Holmes-Farley · Feb 26, 2017

How did you measure this?

GFO is a fine way to go.

scoopsthedog · Feb 26, 2017

Measured via Red Sea - thanks for the reply. Is it unusual to have NO3 at zero and PO so high? I assumed they were tied together

Randy Holmes-Farley · Feb 26, 2017

scoopsthedog said:
Measured via Red Sea - thanks for the reply. Is it unusual to have NO3 at zero and PO so high? I assumed they were tied together

No, they are not tied together. Denitrification will lower nitrate while having little impact on phosphate.

scoopsthedog · Feb 26, 2017

Randy Holmes-Farley said:
No, they are not tied together. Denitrification will lower nitrate while having little impact on phosphate.

Thanks again final question. I was reading your reply on another forum about carbon dosing tied to phosphate. I dose Vitamin C daily and was wondering if I should keep that up or pause while my Phosphate is high and NO3 is zero.

Randy Holmes-Farley · Feb 27, 2017

Vitamin C will continue to drive down nitrate. It could get too low, but it might not. It won't do much for phosphate.

scoopsthedog · Feb 27, 2017

Randy Holmes-Farley said:
Vitamin C will continue to drive down nitrate. It could get too low, but it might not. It won't do much for phosphate.

You've been very generous with your time replying to my questions so I will bother you once again. I've done a 15% water change and have dialed in my skimmer but still have very high phosphates. any thoughts on a short-term solution while I work on a longer-term one

Randy Holmes-Farley · Feb 27, 2017

scoopsthedog said:
You've been very generous with your time replying to my questions so I will bother you once again. I've done a 15% water change and have dialed in my skimmer but still have very high phosphates. any thoughts on a short-term solution while I work on a longer-term one

GFO can be a reasonably rapid way to reduce phosphate. Water changes generally are not the best since not all phosphate is in the water column at any given moment (a large amount can be bound to calcium carbonate surfaces), so even a 100% change doesn't drop phosphate to zero.

LostInTheDark · Feb 27, 2017

I found that dosing a small amount of nitrates has lowered my Phosphates. My nitrates always showed zero and phosphates would be .1 when tested. In trying to raise my nitrates for better color on the corals, my phosphates now stay about .02 or so.

scoopsthedog · Feb 27, 2017

LostInTheDark said:
I found that dosing a small amount of nitrates has lowered my Phosphates. My nitrates always showed zero and phosphates would be .1 when tested. In trying to raise my nitrates for better color on the corals, my phosphates now stay about .02 or so.

What would increase nitrates that would not increase phosphate

LostInTheDark · Feb 27, 2017

They are two different things. I dose 10 ml a day of Potassium Nitrate to keep my nitrates at 5 or less. Phosphates are added to the tank in fish food.