How to manage sustainable, low phosphates but not zero.

[csb123]

My tank is happiest at a nitrate of 5

 

[Randy Holmes-Farley]

So, I have taken out all GFO and my phosphate is 0.0

I have been dosing Trion Phosphorus beta, at 0.1ml >1.0ml and testing after each, it did not change my phosphate from 0.0

Tonight I fed a cube of miss shrimp (frozen) and 2 hours after feeding my phosphate is 0.06 (Hanna checker)

I am going to test daily, possibly twice daily until I know what's needed to maintain this. I have a large refugium but I've always used GFO to maintain low Phosphates. I'm hoping to perhaps increase my lighting strength and encourage my algae to grow more.

Should I be dosing NOO X during this time too? My Nitrates are 5-10ppm (salifert kit) ?

I would not be dosing NOPOX if the goal is to reduce nitrate since yours is fine. If the goal is to create bacteria for filter feeders, organic carbon dosing is fine, but keep a close eye on the nitrate that it does not drop much.

It takes a lot of phosphate dosing to start to get readings as most of it will bind to rock and sand.

 

[Fisherman Joe]

Thanks Randy. Your help is massively appreciated.

I was reading your articles on Phopstaes from decades ago while in bed last night and didn’t fall asleep. Compliment intended.

Few more questions please;

So when I feed frozen my phosphate jumps to 0.06 and then back to zero. How do I maintain a stable low level?

Should I be running granular activated carbon (GAC) all the time? My redox is around 300mv.

What level of high nitrates would warrant NO : PO X dosing?

When my PO4 creeps up towards 0.1 I see brown patches on my sand quickly. See pic. If I try to increase flow I get a lot of detritus in my water column. And advice?

 

[Fisherman Joe]

Rest of the tank for reference.

 

[Graffiti Spot]

What ever happened to running a certain amount of gfo in a reactor to keep po4 unreadable? I used to do that and feed the fish heavy while making sure the change the gfo when it expired. Just because I was reading 0 didn’t mean I had no po4 in the water. The fish were eating like hogs and there was certainly po4 available for the corals. I think things have went very far from this method which worked awesome for me, maybe not awesome for people who didn’t understand how the method works though. And I think a lot of the no readable po4 kills corals talk comes from people who messed up. It’s all about starting slow and reading your corals.

 

[Saltyreef]

What ever happened to running a certain amount of gfo in a reactor to keep po4 unreadable? I used to do that and feed the fish heavy while making sure the change the gfo when it expired. Just because I was reading 0 didn’t mean I had no po4 in the water. The fish were eating like hogs and there was certainly po4 available for the corals. I think things have went very far from this method which worked awesome for me, maybe not awesome for people who didn’t understand how the method works though. And I think a lot of the no readable po4 kills corals talk comes from people who messed up. It’s all about starting slow and reading your corals.

I ran a successful reef tank for years with nearly undetectable nutrients (slightly elevated phos @ .01 to .02 and 0 nitrates)
No dinos, no major issues, great coloration.

Then i started dosing nitrates in fear after reading thru one of the dino threads.
Threw everything out of whack.
Ive been trying to stabilize tank over the last 6 months with lots of casualties in my coral collection sadly.

Live and learn. Going back to old methods has shown promising results thus far.


Go slow, and be very careful.

 

[Randy Holmes-Farley]

Thanks Randy. Your help is massively appreciated.

I was reading your articles on Phopstaes from decades ago while in bed last night and didn’t fall asleep. Compliment intended.

Few more questions please;

So when I feed frozen my phosphate jumps to 0.06 and then back to zero. How do I maintain a stable low level?

Should I be running granular activated carbon (GAC) all the time? My redox is around 300mv.

What level of high nitrates would warrant NO : PO X dosing?

When my PO4 creeps up towards 0.1 I see brown patches on my sand quickly. See pic. If I try to increase flow I get a lot of detritus in my water column. And advice?

You likely cannot maintain it unchanging after feeding. You just want it to average out to a nonzero level.

I'd use GAC to reduce yellowing and removing toxins, but not based on ORP readings.

I chose to dose vinegar to drive bacterial growth, rather than reduce nitrate, but I wouldn't dose organic carbon for the purpose of reducing nitrate unless it was over 20 ppm.

 

[Daniel92481]

Chasing numbers is a dangerous game. Now that your phosphate is 0.06, test it like a madman every day, watch the amount you are feeding and adjust accordingly.

 

[Fisherman Joe]

My problems have certainly come about after taking the GFO off and seeing a spike.

I used to put a little GFO in the tank and leave it running really slow to keep the PO4 at low levels.

I think the key is stability. Not chasing numbers.

 

[Graffiti Spot]

I ran a successful reef tank for years with nearly undetectable nutrients (slightly elevated phos @ .01 to .02 and 0 nitrates)
No dinos, no major issues, great coloration.

Then i started dosing nitrates in fear after reading thru one of the dino threads.
Threw everything out of whack.
Ive been trying to stabilize tank over the last 6 months with lots of casualties in my coral collection sadly.

Live and learn. Going back to old methods has shown promising results thus far.


Go slow, and be very careful.

I feel like a lot of people have been scared into running higher nutrients. I am running my tank like it’s the 90s. I won’t be dosing any po4 I am sure of it. And I will most likely be running gfo for a while. I won’t let a 0 reading make me change anything I have been doing for all these years. My fish love it when it’s reading zero because they just get extra food
I feel bad for the people who are cought up in dumping po4 into their tanks daily. We never used to have to do that and I am curious as to why so many people feel like they have to do this now.

 

[Fisherman Joe]

You make a good point.

i was running at zero phosphates and feeding lots BUT my corals colour was mild. They were out feeding well but little colour.

I’m trying to maintain low PO4 and see what that does.

 

[X-37B]

I see. And that's the only method of phos removal you are using?
What's the idea behind dripping it directly into the skimmer? I thought the normal method would be to dose it directly into the tank or sump, which is what I have been doing... The immediate removal of the flocculants? If the flocculants were to remain too long in the tank, would they "releach" some po4 back in?

I feel like a lot of people have been scared into running higher nutrients. I am running my tank like it’s the 90s. I won’t be dosing any po4 I am sure of it. And I will most likely be running gfo for a while. I won’t let a 0 reading make me change anything I have been doing for all these years. My fish love it when it’s reading zero because they just get extra food
I feel bad for the people who are cought up in dumping po4 into their tanks daily. We never used to have to do that and I am curious as to why so many people feel like they have to do this now.

Agree. I think to many just get caught up in numbers and dont really have a handle on what their tank is doing.
I want to run my tank at .03 as an example.
Just a bad example as to the numbers game without any real understanding of whats going on.
My po4 .02-.04. I check maybe once a month.
Sometimes it tests out at zero. I know their is po4 as my glass gets green every 2 days or so.
No3 runs 1-2 and sometimes it test out as <1 or barely readable.
Tank looks good. Fish are fed 3-4 times a day why change anything.

These nutrient numbers are like alk only worse imo.
Example:
I can be at an lfs and people ask me what alk I run, 7-7.3. Then proceed to tell me I need 9.
I talk to them awhile and now they want to reduce their alk.
Or they say lfs runs 9. I ask have you checked their alk levels?
No but their tank looks good.
I get home yesterday and test lfs alk. Its 10.5 even after lfs says its never over 9.

I know many people that just cant stop changing things in their tanks, even when things look good.

 

[Fisherman Joe]

One of my bug warning flags is when a person in a LFS is 100% confident on their parameters. As we know in this hobby, you can never be 100%.

Anyway, I have stopped dosing NO : PO X as my nitrate is 5ppm. I thought 10ppm was high but in future I won’t dose until it’s up towards 20ppm.

Now without any GFO, only running GAC and the skimmer, I can’t get my phosphate up. It’s reading 0.0 all the time. After I feed a cube of frozen it jumps to 0.06 then back to 0.0 over a 10 hours or so.

Should I just continue to feed and test until it’s more stable between 0.1 and 0.01?

 

[Fisherman Joe]

So, about a week after removing my GFO and stopping dosing all carbon (still running (GAC) my PO4 was 0.02 yesterday and 0.04 today after feeding heavily. I’m now going to have a few days of light feeding and see what happens.

When would you think about adding the GFO back on?

Also my AI Fuge light is only running at 50% brightness but for 12 hours (reverse cycle). Should I try to turn that up first to absorb more PO4? Last time I turned that up my cheato started going white.

 

[Randy Holmes-Farley]

So, about a week after removing my GFO and stopping dosing all carbon (still running (GAC) my PO4 was 0.02 yesterday and 0.04 today after feeding heavily. I’m now going to have a few days of light feeding and see what happens.

When would you think about adding the GFO back on?

Also my AI Fuge light is only running at 50% brightness but for 12 hours (reverse cycle). Should I try to turn that up first to absorb more PO4? Last time I turned that up my cheato started going white.

I would not resume any GFO until phosphate is clearly rising at or above 0.1 ppm.

 

[bam123]

Feed heavy but consistent. Measure phosphate daily for 1 week. Titrate Ephosphate to desired results. THis is what I have done for my tank with a small ice cap algae scrubber, consistent sock changes and 2 percent (AWC) daily water change to keep my levels at .05ppm phosphate. Hope it helps.

 

[Fisherman Joe]

I would not resume any GFO until phosphate is clearly rising at or above 0.1 ppm.

Thank you!

Anytime I seem to get above 0.06 I get brown patches on the sand, Cyano.

On its own this if fine, but I feel it quickly starts to absorb some PO4 and offset the result I see. My PO4 can quickly head backdown to 0.0 and then I notice a heavy film of Cyano in a blind spot at the back of my tank behind the rock.

I have two MP40 power heads in a 450L tank (48” x 24” x 32”) and they are set to about 50% power each (see pic above). When I raise the flow anymore I get lots of sediment in the water column.

Sorry to go over the basics but I really want to build the right habits. Managing stable but low nutrients, consistently, is the final peice of the puzzle for me to get really good colour in my corals.

What do you do when this happens?

 

[Fisherman Joe]

My PO4 is now steady after 0.04.

I think the increased flow in the tank (I turned the power heads up) and the increased NO3 2.0>5.0 has helped suppress the Cyano growth.

would you worry about 0.04 vs 0.02 PO4 etc, or just leave it so long as it’s below 0.1?

 

[Sallstrom]

For stability in low phosphate it's hard with GFO, if you don't use very little GFO and change it often IMO. But if using GFO and the phosphate is low, I usually leave the old GFO in the filter and hope for it to leak some phosphate back to the tank water. If it works, I'm not sure

If you need to reduce PO4 but still are low in NO3, you can dose nitrate and a carbon source to reduce PO4. We do this now and then in several coral tanks at my work. Mostly larger tanks. This way is easiest with well calibrated dosing pumps, to change things slowly and finally reach stable values. So it's a long term project.

Most important is to know your tank and how your tank reacts to low nutrients. In older tanks you might have some biomass/dirt that might add PO4 to the water column if PO4 gets low in the water. Newer or cleaner tanks might react in other ways, with dull colours on the corals and Cyano outbreaks. So less margin.

It's also important to check your corals and not only the test results. You can run a great tank with Hanna Checker showing zero PO4, or you can get into problems, depending on how your tank works. You shouldn't compare too much with how other run their tanks IMO.

Your corals will help you know if the level is okay or not. They usually look unhappy at very low levels of PO4, if you don't have a high input, high export tank - then a very low reading might work fine.
Cyanobacteria can also be a way to see if NO3 or PO4 are "too" low.

And also, to keep PO4 stable, it's easier if the input of food/nutrients is the same every day, of coarse. Then you can build up your way to keep it where you want, with dosing PO4, feeding more or less, dosing carbon source etc.

Some idea

Good luck!

 

[Randy Holmes-Farley]

My PO4 is now steady after 0.04.

I think the increased flow in the tank (I turned the power heads up) and the increased NO3 2.0>5.0 has helped suppress the Cyano growth.

would you worry about 0.04 vs 0.02 PO4 etc, or just leave it so long as it’s below 0.1?

That value is just fine.