Phosphates, Color and Growth

dave57 · Jan 7, 2018

I’ve been reading mixed views on phosphate levels and their impact on coral health and coloration, some people suggest low range, less than or equal to 0.03 and others have suggested to balance nutrients and maintain them according to Redfield Ratio...to minimize algae growth and improve growth and color, for example running nitrates at 5 po4 should be around the 0.3 range... what are your guys thoughts, opinions and experiences? Post pics if possible And state which phosphate test you utilize. Thank you guys I appreciate the input.

tdileo · Jan 7, 2018

IME: more PO4 (within an acceptable range, of course) = better growth and slightly lesser color, depending on opinion, lighting, and the type of coral. Vice versa goes for low PO4. I think it’s also important to keep in mind that low PO4 means you must keep a lower alk, which is another reason that corals will grow slower. LPS and soft corals also typically like slightly more dirty water, but assuming you are speaking only about SPS, I believe somewhere in the middle is optimal. Personally I prefer better growth over perfect color. This is all just from my experiences and my opinions, so it may differ for other people. I like to keep my PO4 at about .05 measured with a Hanna ULR Checker.

Mark Waltermire · Jan 7, 2018

tdileo said:
IME: more PO4 (within an acceptable range, of course) = better growth and slightly lesser color, depending on opinion, lighting, and the type of coral. Vice versa goes for low PO4. I think it’s also important to keep in mind that low PO4 means you must keep a lower alk, which is another reason that corals will grow slower. LPS and soft corals also typically like slightly more dirty water, but assuming you are speaking only about SPS, I believe somewhere in the middle is optimal. Personally I prefer better growth over perfect color. This is all just from my experiences and my opinions, so it may differ for other people. I like to keep my PO4 at about .05 measured with a Hanna ULR Checker.

Why is it that if you have lower phosphates that you will need to have lower alk? I run my tank at .03ppm phosphates and have the alk right at 9DHK.

happyhourhero · Jan 7, 2018

My personal experience has been not caring or even checking p04 leads to great color and growth. When I started checking and doing everything I could to keep it at that .03 Target everyone talks about, my tank was awful. Since going back to feeding heavy and not checking, everything has rebounded and has great color and growth.

tdileo · Jan 7, 2018

Mark Waltermire said:
Why is it that if you have lower phosphates that you will need to have lower alk? I run my tank at .03ppm phosphates and have the alk right at 9DHK.

Not necessarily .03, but many people that run ULNS systems experience RTN and STN issues due to high alkalinity. I’m not completely sure of the scientific reasoning behind it to be honest.

tdileo · Jan 7, 2018

happyhourhero said:
My personal experience has been not caring or even checking p04 leads to great color and growth. When I started checking and doing everything I could to keep it at that .03 Target everyone talks about, my tank was awful. Since going back to feeding heavy and not checking, everything has rebounded and has great color and growth.

I think that what a lot of people forget is that phosphates are food for your corals, not just a factor that is there and effects color/growth. Not enough can cause pale coral and meh growth, but too much will cause algae problems. I believe that there is a pretty wide range of acceptable PO4 levels. A lot of people are going to think I’m crazy, but I think that anywhere between .04 and .15 are good.

Luno · Jan 7, 2018

It really depends on how you run your tank. When you run an ULNS the idea is big feeds even bigger export. There is plenty of nutrients for the coral but unused is exported quickly.

TX_Punisher · Jan 7, 2018

I just started my 200 7 months ago. I've been going back and forth between how to keep this thing. I've talked to a few people about this subject as well. I'm wondering if I can get some thoughts?

About 160g of water volume
8 bulb t5 with 5 blue +, 2 actinic and 1pp soon at add reef brite xho actinic
Elite 200 internal skimmer on 3.
Params: 1.025sg, 78 degrees, po4 2ppb on Hannah phosphorus =.006 ppm, 5-10 nitrates (dosed sodium nitrate too much but will do large water change this week to get to 2-5), ca 460, mg currently 1450, alk 9.8. I'm using fritz salt which has higher alk than my reef crystals was using. Mg seems higher as well.

I just added an order from fraghouse and several pieces went green. I've had pieces in there 4-5 mos and really haven't seen much growth out of anything other than the acans

Aside from lowering the alk, do those numbers seem appropriate for growth and coloration? I'm feeding one cube of mysis a day with pellets on an auto feeder as well. I'm also running biopellets.

Any thoughts?

cwiggins · Jan 25, 2018

tdileo said:
Not necessarily .03, but many people that run ULNS systems experience RTN and STN issues due to high alkalinity. I’m not completely sure of the scientific reasoning behind it to be honest.

What is RTN and STN?

CoralWealth · Jan 25, 2018

TX_Punisher said:
I just started my 200 7 months ago. I've been going back and forth between how to keep this thing. I've talked to a few people about this subject as well. I'm wondering if I can get some thoughts?

About 160g of water volume
8 bulb t5 with 5 blue +, 2 actinic and 1pp soon at add reef brite xho actinic
Elite 200 internal skimmer on 3.
Params: 1.025sg, 78 degrees, po4 2ppb on Hannah phosphorus =.006 ppm, 5-10 nitrates (dosed sodium nitrate too much but will do large water change this week to get to 2-5), ca 460, mg currently 1450, alk 9.8. I'm using fritz salt which has higher alk than my reef crystals was using. Mg seems higher as well.

I just added an order from fraghouse and several pieces went green. I've had pieces in there 4-5 mos and really haven't seen much growth out of anything other than the acans

Aside from lowering the alk, do those numbers seem appropriate for growth and coloration? I'm feeding one cube of mysis a day with pellets on an auto feeder as well. I'm also running biopellets.

Any thoughts?

How many fish do you have? I would feed a lot more. I feed around 6 cubes a day of frozen food in my 180.

nautical_nathaniel · Jan 25, 2018

cwiggins said:
What is RTN and STN?

Rapid and Slow Tissue Necrosis

TX_Punisher · Jan 25, 2018

codydemmel4 said:
How many fish do you have? I would feed a lot more. I feed around 6 cubes a day of frozen food in my 180.

I just added 5-6 fish in the last two weeks. Previously had 5.

CoralWealth · Jan 25, 2018

TX_Punisher said:
I just added 5-6 fish in the last two weeks. Previously had 5.

small fish or what fish do you have? Also, as you said I would lower your alk closer to 8 or maybe lower. That is up to you but with lower nutrients and your high alk, it isnt usually a good combination especially with your strong lights too

TX_Punisher · Jan 25, 2018

codydemmel4 said:
small fish or what fish do you have? Also, as you said I would lower your alk closer to 8 or maybe lower. That is up to you but with lower nutrients and your high alk, it isnt usually a good combination especially with your strong lights too

Mostly smaller at this point.
1 md yellow tang
1 medium powder blue
1 small orange shoulder
1 medium filefish
1 large male lyretail
3 female lyretails
1 medium misbar
1 diamond goby
1 small yellow coris wrasse

I switched to fritz as I've heard good things and my lfs had a crazy sale. But upon mixing I'm seeing 10dkh far higher than RC. I picked up some muratic acid yesterday to lower my mix water alk to maybe 9-9.5 and to slowly do some water changes to bring those numbers down. I'll probably switch back to RC by March.

I am also running biopellets at about 1/2 the dose. I'm dosing sodium nitrate as well and have been surprised no3 doesn't seem to move. I figured the biopellets would consume some?

BoomCorals · Jan 25, 2018

tdileo said:
IME: more PO4 (within an acceptable range, of course) = better growth and slightly lesser color, depending on opinion, lighting, and the type of coral. Vice versa goes for low PO4. I think it’s also important to keep in mind that low PO4 means you must keep a lower alk, which is another reason that corals will grow slower. LPS and soft corals also typically like slightly more dirty water, but assuming you are speaking only about SPS, I believe somewhere in the middle is optimal. Personally I prefer better growth over perfect color. This is all just from my experiences and my opinions, so it may differ for other people. I like to keep my PO4 at about .05 measured with a Hanna ULR Checker.

My experience mimics this, except that I don't find corals grow any slower. I keep my PO4 at around .05 and nitrate around 1-2. My alk is 7-8 dkh. I get great color and fast growth. My .02

TX_Punisher · Jan 25, 2018

BoomCorals said:
My experience mimics this, except that I don't find corals grow any slower. I keep my PO4 at around .05 and nitrate around 1-2. My alk is 7-8 dkh. I get great color and fast growth. My .02

So on the Hannah ulr phosphorus
Meter you're at about 17 (ppb)? I was at 2ppb ( .006 ppm) the last time I checked but I'm sure it's higher now.

Thanks

BoomCorals · Jan 25, 2018

TX_Punisher said:
So on the Hannah ulr phosphorus
Meter you're at about 17 (ppb)? I was at 2ppb ( .006 ppm) the last time I checked but I'm sure it's higher now.

Thanks

Yea I'm usually in the 15-20 range on the hannah ulr.