rt67ghy
Member
I'd like to start a discussion on phosphate control with only macroalgae. I'd first like to share my experience and then would like to hear other people's experiences on this topic.
First for some background information. I set up my tank (220 gallon DT + sump) in May 2014 and had a few small fish, a couple of nems, a couple of LPS corals and a few softies until June 2015 when I started slowly adding some more LPS corals. I didn't worry about nitrates (NO3) or phosphates (PO4) until January 2015 when I started using GFO after I found my PO4 to be 0.5 ppm with my new Hanna ULR phosphorus checker.
After that I tested PO4 every week and added GFO in a media reactor to control it. My goal was always to keep it around 0.1 ppm. I would add anywhere from 50g to 300g GFO once a week or every 2 weeks. With the increased feeding of my growing population of anemones and LPS corals (most of which I target feed) I found that from September 2015 I was adding 200g of GFO every week. I started regenerating the GFO to save on expenses.
I installed a DIY algae scrubber (not a very good one) in January 2015 and was harvesting around 90g of wet algae every 2 weeks. After some improvements to the scrubber I was able to increase the harvest to 160g every 2 weeks from December 2015.
I got 2 balls of chaeto in March 2015 and kept them in my fuge with cheap led lights where they were growing slowly and only once harvested some chaeto 8 months later. In December I added a 32 W CFL light to my fuge to increase chaeto growth. Also I noticed some strands of chaeto had escaped into the next chamber of my sump where I have my algae srubber and, more importantly, 3 X 24 W CFL lights for my scrubber.
The chaeto is now growing much better especially under the scrubber lights and I harvested 115g of chaeto yesterday from the 2 chambers. To my surprise I found that my PO4 has remained between 0.04 to 0.06 ppm for one month without the need of adding any GFO. Although not scientific, I have not decreased the amount of food I'm feeding to the tank every day.
Although it may be too early to tell, I believe I may be able to control my NO3 and PO4 with macroalgal growth. There is one more thing to add. From October 2015 I have been adding 5ml of Kent Marine's Iron and Manganese every alternate day to encourage phytoplankton growth to feed my gonioporas. These elements may be exhausted rapidly by micro and macroalgae and may limit their growth even if there is enough NO3 and PO4 in the water. It may be worthwhile to mention I only change 25% of my water once a month.
First for some background information. I set up my tank (220 gallon DT + sump) in May 2014 and had a few small fish, a couple of nems, a couple of LPS corals and a few softies until June 2015 when I started slowly adding some more LPS corals. I didn't worry about nitrates (NO3) or phosphates (PO4) until January 2015 when I started using GFO after I found my PO4 to be 0.5 ppm with my new Hanna ULR phosphorus checker.
After that I tested PO4 every week and added GFO in a media reactor to control it. My goal was always to keep it around 0.1 ppm. I would add anywhere from 50g to 300g GFO once a week or every 2 weeks. With the increased feeding of my growing population of anemones and LPS corals (most of which I target feed) I found that from September 2015 I was adding 200g of GFO every week. I started regenerating the GFO to save on expenses.
I installed a DIY algae scrubber (not a very good one) in January 2015 and was harvesting around 90g of wet algae every 2 weeks. After some improvements to the scrubber I was able to increase the harvest to 160g every 2 weeks from December 2015.
I got 2 balls of chaeto in March 2015 and kept them in my fuge with cheap led lights where they were growing slowly and only once harvested some chaeto 8 months later. In December I added a 32 W CFL light to my fuge to increase chaeto growth. Also I noticed some strands of chaeto had escaped into the next chamber of my sump where I have my algae srubber and, more importantly, 3 X 24 W CFL lights for my scrubber.
The chaeto is now growing much better especially under the scrubber lights and I harvested 115g of chaeto yesterday from the 2 chambers. To my surprise I found that my PO4 has remained between 0.04 to 0.06 ppm for one month without the need of adding any GFO. Although not scientific, I have not decreased the amount of food I'm feeding to the tank every day.
Although it may be too early to tell, I believe I may be able to control my NO3 and PO4 with macroalgal growth. There is one more thing to add. From October 2015 I have been adding 5ml of Kent Marine's Iron and Manganese every alternate day to encourage phytoplankton growth to feed my gonioporas. These elements may be exhausted rapidly by micro and macroalgae and may limit their growth even if there is enough NO3 and PO4 in the water. It may be worthwhile to mention I only change 25% of my water once a month.
