Need help getting PO4 stable

[Trooper182]

So I have some questions regarding my phosphate levels. My 75g has been up since Aug last year. I have a mix of LPS and softies in my tank. Every time I test my PO4 reads almost 0. Using my Hanna phosphorus tester I get 1 PPB which translates to 0.003PPM phosphate. Now I do keep sea lettuce in my refugium section and know this is probably playing a role in my low numbers. The thing is I have tried dosing Neophos in the tank over a few days and when I do I start to see hair algae creep up in the MD. If I don't dose it eventually goes away. I tested my water on the 6th of March and got the below readings. I dosed 20ml of neophos and tested an hr later and showed 20PPB (.06PPM.) I tested the next day and at the same time and it dropped to 6PPB. Today it was down to 1. I'm trying to achieve a stable .03PPM. How should I go about correcting this? I feel that the lack of phosphates is also inhibiting good growth in my corals, mainly my GSP. Everything looks healthy, just lacking growth. Should I remove all the sea lettuce and then dose it to bring the level up? What should I do if nuisance algae appear in the MD?

75g with 20g sump, 2 gyre Wavemakers, and light schedule in the photos. Water changes are done 20% every 2 weeks.

Alk- 11.7
Salinity- 1.026
Ammonia- 0
NO3- 8.6
NO2- 0
PO4- 1PPB
Ph- 8.2
Cal- 430
Mag- 1380
Temp 79 degrees

 

[bradreef]

Simply add more nutrients and reduce removal. Feed more, reduce the refugium light time.

 

[Trooper182]

Simply add more nutrients and reduce removal. Feed more, reduce the refugium light time.

I have a auto feeder that feeds pellets 3 times a day. I also feed flake food once a day and mysis x2 a week. Corals are spot fed x2 a week with reef roids. Fug light is on from 10pm-3am and that's backed off of what it previously was based on recommendations.

 

[bradreef]

Either open the auto feeder a little more or take the refugium offline, cut the sea lettuce in half?

 

[Trooper182]

Either open the auto feeder a little more or take the refugium offline, cut the sea lettuce in half?

I'm thinking pulling the lettuce and then dosing the neophos again and seeing what the drop rate is.

 

[gbroadbridge]

You simply need to add more phosphate - at the moment a lot is being sequestered by the rock and substrate.

Eventually, when they have soaked up enough phosphate, they act as a buffer which can be good or bad depending on the level they have settled at.

It takes just as long to bring it down as it does to take it up, so go slow.

 

[vetteguy53081]

So I have some questions regarding my phosphate levels. My 75g has been up since Aug last year. I have a mix of LPS and softies in my tank. Every time I test my PO4 reads almost 0. Using my Hanna phosphorus tester I get 1 PPB which translates to 0.003PPM phosphate. Now I do keep sea lettuce in my refugium section and know this is probably playing a role in my low numbers. The thing is I have tried dosing Neophos in the tank over a few days and when I do I start to see hair algae creep up in the MD. If I don't dose it eventually goes away. I tested my water on the 6th of March and got the below readings. I dosed 20ml of neophos and tested an hr later and showed 20PPB (.06PPM.) I tested the next day and at the same time and it dropped to 6PPB. Today it was down to 1. I'm trying to achieve a stable .03PPM. How should I go about correcting this? I feel that the lack of phosphates is also inhibiting good growth in my corals, mainly my GSP. Everything looks healthy, just lacking growth. Should I remove all the sea lettuce and then dose it to bring the level up? What should I do if nuisance algae appear in the MD?

75g with 20g sump, 2 gyre Wavemakers, and light schedule in the photos. Water changes are done 20% every 2 weeks.

Alk- 11.7
Salinity- 1.026
Ammonia- 0
NO3- 8.6
NO2- 0
PO4- 1PPB
Ph- 8.2
Cal- 430
Mag- 1380
Temp 79 degrees

Feed more to fish but without overfeeding
Decrease skimming time if skimmer applies
Lengthen time between water changes
Refrain from use of chemicals

Also get an outside test at an LFS and have them test to verify your readings

 

[Trooper182]

You simply need to add more phosphate - at the moment a lot is being sequestered by the rock and substrate.

Eventually, when they have soaked up enough phosphate, they act as a buffer which can be good or bad depending on the level they have settled at.

It takes just as long to bring it down as it does to take it up, so go slow.

If I were to start daily dosing what would you say would be a good amount? Obviously I can't test consumption every day as ill run through reagent and hanna refills aren't cheap. Other issue is last time I tried daily dosing after a few days hair algae started to take off in the display

 

[Trooper182]

Feed more to fish but without overfeeding
Decrease skimming time if skimmer applies
Lengthen time between water changes
Refrain from use of chemicals

Also get an outside test at an LFS and have them test to verify your readings

I'm going to test on Saturday morning and also take a sample to the lfs for a test.

 

[Aqua Man]

dosed 20ml of neophos and tested an hr later and showed 20PPB (.06PPM.) I tested the next day and at the same time and it dropped to 6PPB. Today it was down to 1. I'm trying to achieve a stable .03PPM

If 20ml gave you .06 and want to be at .03. Then dose 10ml a day. Test once a week and adjust dose as needed.

 

[Trooper182]

Ok so update:
I started dosing Neophos last Thursday evening (9 march) 15ml every evening at the same time. Skipped testing during that time and tested this evening. My ulr phosphorus tester showed 21PPB, so that would be 0.064PPM phosphate. So should I now not dose this evening and let things sit for 24hr and test tomorrow to see the consumption? Ideally I want to keep at .03PPM phosphate.

 

[Lavey29]

Ok so update:
I started dosing Neophos last Thursday evening (9 march) 15ml every evening at the same time. Skipped testing during that time and tested this evening. My ulr phosphorus tester showed 21PPB, so that would be 0.064PPM phosphate. So should I now not dose this evening and let things sit for 24hr and test tomorrow to see the consumption? Ideally I want to keep at .03PPM phosphate.

You want .05 to .1 phosphate for a safe level. Sounds like your current dose and number is good. If you feed corals more like reef roids or pellets for fish your phosphate will increase without dosing probably.

 

[Trooper182]

You want .05 to .1 phosphate for a safe level. Sounds like your current dose and number is good. If you feed corals more like reef roids or pellets for fish your phosphate will increase without dosing probably.

Thanks, yea I feed pellets 4x day and reef roids 2x week and was still seeing 0. If I can get this stable I would like to not have to dose or dose every so often. I think the 0 phosphate has been inhibiting good coral growth and coralline as all the other parameters are good.

 

[Lavey29]

Thanks, yea I feed pellets 4x day and reef roids 2x week and was still seeing 0. If I can get this stable I would like to not have to dose or dose every so often. I think the 0 phosphate has been inhibiting good coral growth and coralline as all the other parameters are good.

I had to double dose neophos and neonitro for many weeks before my numbers stabilized. What you need to watch is all the phosphate you are adding is getting bound in rocks and sand. Then you reach an equilibrium point. Then the rocks and sand become over saturated and begin to leach in the water. Then your phosphate begins to creep up and you can't control it. This is where my tank is now. My phosphate crept up to .51. Normal methods like GFO and Phosguard would not lower it but phosphate RX has been working to bring it down. It seems to stay around .15 now with phosphate RX. Once the rocks and sand bleed out the process starts again.

 

[Trooper182]

Ok so update:

I dosed 10mg for another week and tested last Thursday (23 march) and I got 37ppb phosphorus (0.113ppm phosphate.) I stopped dosing and let it sit for the last few days. Today I tested and got 31ppb (0.095ppm phosphate.) So where should I go from here? Does the fact that it didn't rapidly drop down to 0 again mean that it is stabilizing? Should I dose a certain amount a day or week to maintain?

 

[Lavey29]

Ok so update:

I dosed 10mg for another week and tested last Thursday (23 march) and I got 37ppb phosphorus (0.113ppm phosphate.) I stopped dosing and let it sit for the last few days. Today I tested and got 31ppb (0.095ppm phosphate.) So where should I go from here? Does the fact that it didn't rapidly drop down to 0 again mean that it is stabilizing? Should I dose a certain amount a day or week to maintain?

It will take maybe 2 or 3 weeks of daily or every other day testing to determine if your phosphate number is consistent or if you need periodoc dosing. Phosphate is tricky because a lot of the things we put in our tank can raise it such as pellets or reef roids. You kind of have to watch it close for awhile until it seems like your system of feeding and other additives balances with the phosphate consumption of the tank. I still check mine several times a week.