Phosphates are up and down like crazy

[jat148]

Hiya gang,

In my 200L reef tank, the Phosphate levels have always been on the high side - higher than I'd like, so I've been working hard to get them under control. The problem is that I can't seem to keep them at any level for any length of time. Here's a quick chart of Phosphate records so far in June:
Date: ppm
02 - 0.12
03 - 0.05
04 - 0.08
05 - 0.10
06 - 0.10
08 - 0.12
09 - 0.08
10 - 0.08
11 - 0.12
12 - 0.09
13 - 0.15
14 - 0.07
16 - 0.11
Other levels are ok, I think:
Nitrate = 0.5
alk = 9.1
salinity = 1.025
calc = 430
mag = 1320
pH = 8.2
temp = 27C

I've changed the filters on my RO/DI water filter, and when tested the water is coming out at 0.04 ppm phosphates.
There's a Bubble Magus curve 7 protein skimmer, which works pretty well. I change the tank filters often, and keep the glass clean.
Lots of clean up crew in there, and only 4 little cromis, a wrasse and a gobi in terms of fish, and they don't get fed very much at all - a tiny pinch.
A fluidised reactor has Nutrifix NP media inside, plus Rowaphos, which doesn't seem to help.
I'm also now dosing 'Agent Green phosphate destroyer' (Lanthanam Chloride) at 2mL per day.

The only nutrient is Redsea A&B at 8mL per day for the coral - could this be adding to phosphates?
The suggested dose on that is 4mL per 100L , so I'm not over on that. There's a few corals (zoa, goni, monti, etc) and lots of coraline too.

Does anyone have a suggestion? I'm keen to keep trying different ideas, but it's bothering me where the phosphate is actually coming from?
Could it be the sand??

many thanks,
James

 

[PPBlimpy]

Personally if you aren't trying to keep SPS I wouldn't worry much about those numbers. Keep up with the maintenance like you are and let it ride.

I used to chase phos in my tank, was running GFO and the swings were brutal. I have had good luck with an algea scrubber, though it takes a couple weeks for it to come online. run a refugium and starting a cryptic fuge. next thing is to start farming phyto and copepods and dose weekly.

I try not to ad extra chemicals to the tank anymore. gets time consuming and expensive on a 400G system.

what is the history of your rocks? what is your feeding schedule and how many fish?

 

[Randy Holmes-Farley Verified Community Expert]

All of the values are fine, IMO.

 

[p1u5h13r4m24]

I like to stay between .1-.2. Mainly because I have a ton of coral and they suck up a ton of nutrients

 

[jat148]

Personally if you aren't trying to keep SPS I wouldn't worry much about those numbers. Keep up with the maintenance like you are and let it ride.

I used to chase phos in my tank, was running GFO and the swings were brutal. I have had good luck with an algea scrubber, though it takes a couple weeks for it to come online. run a refugium and starting a cryptic fuge. next thing is to start farming phyto and copepods and dose weekly.

I try not to ad extra chemicals to the tank anymore. gets time consuming and expensive on a 400G system.

what is the history of your rocks? what is your feeding schedule and how many fish?

Thanks very much for that. I'd like to get towards an SPS full tank, but almost everything we've ever bought to put in there hasn't lasted more than a month before it starts to slowly die away.
So I'd like to improve on the numbers - I realise that they're acceptable (I've had far worse) but it's got to be worth the effort if I can get much better conditions for SPS. I've had tanks for 8 yrs now.
The rocks are years old - some are 8 yrs.
The fish population is being kept light on purpose:
4 green cromis
1 purple wrasse
1 gatekeeper boby + shrimp buddy.
They're on a very lite diet currently - because I'm a little obsessed with phosphates.
I thought about a refugium years ago, so we could grow Chaeto, but the sump on this 200L is tiny and it's already full with a skimmer & reactor - plus a few rocks and a heater.

 

[p1u5h13r4m24]

Personally if you aren't trying to keep SPS I wouldn't worry much about those numbers. Keep up with the maintenance like you are and let it ride.

I used to chase phos in my tank, was running GFO and the swings were brutal. I have had good luck with an algea scrubber, though it takes a couple weeks for it to come online. run a refugium and starting a cryptic fuge. next thing is to start farming phyto and copepods and dose weekly.

I try not to ad extra chemicals to the tank anymore. gets time consuming and expensive on a 400G system.

what is the history of your rocks? what is your feeding schedule and how many fish?

Thanks very much for that. I'd like to get towards an SPS full tank, but almost everything we've ever bought to put in there hasn't lasted more than a month before it starts to slowly die away.
So I'd like to improve on the numbers - I realise that they're acceptable (I've had far worse) but it's got to be worth the effort if I can get much better conditions for SPS. I've had tanks for 8 yrs now.
The rocks are years old - some are 8 yrs.
The fish population is being kept light on purpose:
4 green cromis
1 purple wrasse
1 gatekeeper boby + shrimp buddy.
They're on a very lite diet currently - because I'm a little obsessed with phosphates.
I thought about a refugium years ago, so we could grow Chaeto, but the sump on this 200L is tiny and it's already full with a skimmer & reactor - plus a few rocks and a heater.

Hey so your nitrates are super low. They are out of balance to your phos. So you want a 100:1 nitrate to phos ratio. Also with nutrients that low you want to run lower alkalinity. For example I run 10 nitrate, .1 phos, 7.5-8.0 dkh

 

[TangerineSpeedo]

Your levels are fine. If you do not have any algae issues don't worry about it.
The yoyoing of you phosphate is from the fact your sand and rock (some more than others) absorb Po4. when you use media to pull Po4 out of the water column, it is reintroduced by your substrate. this will go on until it hits the equilibrium of the target Po4 level you want to maintain.

 

[p1u5h13r4m24]

Your low nutrients is most likely your issue with not being able to keep anything imo

 

[jat148]

I like to stay between .1-.2. Mainly because I have a ton of coral and they suck up a ton of nutrients

That's interesting. I can keep within that range easily enough, but do you think that coral growth is optimal at that level? I crave huge growth, like the aquarium shop can achieve!

 

[Drewe]

Hiya gang,

In my 200L reef tank, the Phosphate levels have always been on the high side - higher than I'd like, so I've been working hard to get them under control. The problem is that I can't seem to keep them at any level for any length of time. Here's a quick chart of Phosphate records so far in June:
Date: ppm
02 - 0.12
03 - 0.05
04 - 0.08
05 - 0.10
06 - 0.10
08 - 0.12
09 - 0.08
10 - 0.08
11 - 0.12
12 - 0.09
13 - 0.15
14 - 0.07
16 - 0.11
Other levels are ok, I think:
Nitrate = 0.5
alk = 9.1
salinity = 1.025
calc = 430
mag = 1320
pH = 8.2
temp = 27C

I've changed the filters on my RO/DI water filter, and when tested the water is coming out at 0.04 ppm phosphates.
There's a Bubble Magus curve 7 protein skimmer, which works pretty well. I change the tank filters often, and keep the glass clean.
Lots of clean up crew in there, and only 4 little cromis, a wrasse and a gobi in terms of fish, and they don't get fed very much at all - a tiny pinch.
A fluidised reactor has Nutrifix NP media inside, plus Rowaphos, which doesn't seem to help.
I'm also now dosing 'Agent Green phosphate destroyer' (Lanthanam Chloride) at 2mL per day.

The only nutrient is Redsea A&B at 8mL per day for the coral - could this be adding to phosphates?
The suggested dose on that is 4mL per 100L , so I'm not over on that. There's a few corals (zoa, goni, monti, etc) and lots of coraline too.

Does anyone have a suggestion? I'm keen to keep trying different ideas, but it's bothering me where the phosphate is actually coming from?
Could it be the sand??

many thanks,
James

Are you by chance using the Hanna ULR? That thing always gives me wildly different results. Like last week I got 0.14 and immediately tested again and got 0.03, and then immediately after that 0.07.

 

[p1u5h13r4m24]

I like to stay between .1-.2. Mainly because I have a ton of coral and they suck up a ton of nutrients

That's interesting. I can keep within that range easily enough, but do you think that coral growth is optimal at that level? I crave huge growth, like the aquarium shop can achieve!

Ansolutely. The growth rate of sps is effects by such a lower number over .2phos I’m not sure of the exact precentage but people assuming it’s like 6% slower growth over .2

 

[Pistondog]

Hiya gang,

In my 200L reef tank, the Phosphate levels have always been on the high side - higher than I'd like, so I've been working hard to get them under control. The problem is that I can't seem to keep them at any level for any length of time. Here's a quick chart of Phosphate records so far in June:
Date: ppm
02 - 0.12
03 - 0.05
04 - 0.08
05 - 0.10
06 - 0.10
08 - 0.12
09 - 0.08
10 - 0.08
11 - 0.12
12 - 0.09
13 - 0.15
14 - 0.07
16 - 0.11
Other levels are ok, I think:
Nitrate = 0.5
alk = 9.1
salinity = 1.025
calc = 430
mag = 1320
pH = 8.2
temp = 27C

I've changed the filters on my RO/DI water filter, and when tested the water is coming out at 0.04 ppm phosphates.
There's a Bubble Magus curve 7 protein skimmer, which works pretty well. I change the tank filters often, and keep the glass clean.
Lots of clean up crew in there, and only 4 little cromis, a wrasse and a gobi in terms of fish, and they don't get fed very much at all - a tiny pinch.
A fluidised reactor has Nutrifix NP media inside, plus Rowaphos, which doesn't seem to help.
I'm also now dosing 'Agent Green phosphate destroyer' (Lanthanam Chloride) at 2mL per day.

The only nutrient is Redsea A&B at 8mL per day for the coral - could this be adding to phosphates?
The suggested dose on that is 4mL per 100L , so I'm not over on that. There's a few corals (zoa, goni, monti, etc) and lots of coraline too.

Does anyone have a suggestion? I'm keen to keep trying different ideas, but it's bothering me where the phosphate is actually coming from?
Could it be the sand??

many thanks,
James

Your phosphate levels are fine. Stop the lc dosing.
Nitrates are on the low side.

 

[jat148]

Are you by chance using the Hanna ULR? That thing always gives me wildly different results. Like last week I got 0.14 and immediately tested again and got 0.03, and then immediately after that 0.07.

Well yes! I did start to wonder about the meter (because I've tried everything else). I'd hate the Hanna to be the issue, because they're expensive, and I've grown to really prefer it to looking at colour charts.

 

[Drewe]

Are you by chance using the Hanna ULR? That thing always gives me wildly different results. Like last week I got 0.14 and immediately tested again and got 0.03, and then immediately after that 0.07.

Well yes! I did start to wonder about the meter (because I've tried everything else). I'd hate the Hanna to be the issue, because they're expensive, and I've grown to really prefer it to looking at colour charts.

If you have another test kit I'd go ahead and check the Hanna against it, my guess is you're way more stable than it looks at first glance. The quality and consistency of the reagents with Hanna leaves a bit to be desired IMO but I still use them, especially the alk one because it takes 90 seconds to do.

 

[jat148]

Your levels are fine. If you do not have any algae issues don't worry about it.
The yoyoing of you phosphate is from the fact your sand and rock (some more than others) absorb Po4. when you use media to pull Po4 out of the water column, it is reintroduced by your substrate. this will go on until it hits the equilibrium of the target Po4 level you want to maintain.

I didn't know that. I've had the feeling that I'm taking phosphates away, and it's as if they're being replaced. The sand was something I'd began to wonder about. Thanks!

 

[Oldreefer44]

There are plenty of examples of thriving sps dominated systems with much higher PO4 than yours. While NO3 is low I doubt that it is the source of your issues. Might suggest an ICP ms test to help identify or eliminate other possible issues.