Phosphate creep

[Lavey29]

That’s awesome. Now I have to read your build thread.

I never really kept it updated. I had my ups and downs the first year but after the one year mark the tank went through an evolution and just became so much more stable and predictable. I have 37 SPS frags most are mini colonies now and I've only lost one SPS frag after the one year mark due to shipping stress. But I like euphyllia and softs too.

Thank you for your well thought replies.

 

[Fishy888]

No problem. I’ve had my moments too with my system.

 

[shootingstar_reef]

I have not seen significant direct evidence that high phosphates have any negative effect on coral.

 

[Lavey29]

I have not seen significant direct evidence that high phosphates have any negative effect on coral.

There is evidence that high nutrients can lead to browning in corals like SPS. I know when I was dosing aminos to often some of my acros browned out but came back as the nutrients level lowered.

 

[Fishy888]

I have not seen significant direct evidence that high phosphates have any negative effect on coral.

High phosphates can and often do cause coral skeletons to cease growing especially in new tanks with only a few corals.

Newer tanks also have nuisance algae that form until coralline comes in. Algae can smother coral quite easily. It can use allelopathy to fight coral. High phosphates in that environment just throws gasoline on the fire.

 

[gbroadbridge]

So my phosphate has been creeping up. .41 yesterday. I typically use phosguard to keep it in check but might have to use some GFO now to bring it down. However, the tank is booming right now with coral growth and color. I know the potential of algae is increasing but I'm really wondering if I should let it ride and not chase numbers or default to what the proven best standard is for phosphate and bring it back down below .1. My alk is 8.3 on Hanna and nitrates 11. ICP showed my alk at 7.6 so different then the Hanna tester. Sand has been getting whiter too. I know each tank is unique but wonder if I will shoot myself in the foot just letting the phosphate do its thing. I feed frozen, have an oversize skimmer and fuge with huge chaeto. I dose reef actif and PNS probio once a week to prevent organic waste. 20% water change every 3 weeks and dose trace weekly along with alk and cal dose daily.

Anyone really not concerned with their phosphate number?

I think the problem with letting it ride is that it is a potential timebomb ticking away.

One day the cumulative phosphate exposure together with other changes which may not be obvious may be building up and cause some grief - a bit like old tank sydnrome.

If it were me, I'd be looking to stabilise it, and then slowly lowering it back down over a few months to 0.1 to 0.2ppm.

 

[Lavey29]

I think the problem with letting it ride is that it is a potential timebomb ticking away.

One day the cumulative phosphate exposure together with other changes which may not be obvious may be building up and cause some grief - a bit like old tank sydnrome.

If it were me, I'd be looking to stabilise it, and then slowly lowering it back down over a few months to 0.1 to 0.2ppm.

Thanks for making me nervous as I'm getting ready to go to sleep.

 

[Fishy888]

I think the problem with letting it ride is that it is a potential timebomb ticking away.

One day the cumulative phosphate exposure together with other changes which may not be obvious may be building up and cause some grief - a bit like old tank sydnrome.

If it were me, I'd be looking to stabilise it, and then slowly lowering it back down over a few months to 0.1 to 0.2ppm.

It could be that way. Vigilance is a must. There are reefers who have kept systems as high as 1 ppm for years. You just have to know your system. In @Lavey29’s case he’s got enough healthy, growing coral and likely coralline. Coralline uses more phosphates than you think. It’s a type of algae after all.

 

[gbroadbridge]

Thanks for making me nervous as I'm getting ready to go to sleep.

lol. Please don't do anything fast

If you normally use Phosguard just use that rather then switching to Lanthanum Chloride or GFO.
It'll take weeks/months

 

[Fishy888]

lol. Please don't do anything fast

If you normally use Phosguard just use that rather then switching to Lanthanum Chloride or GFO.
It'll take weeks/months

His phosphates are only 0.4 ppm. I doubt he’s going to get much if any nuisance algae considering all the corals in his system. I’d personally leave things as they are but watch things closely.

 

[Lavey29]

It could be that way. Vigilance is a must. There are reefers who have kept systems as high as 1 ppm for years. You just have to know your system. In @Lavey29’s case he’s got enough healthy, growing coral and likely coralline. Coralline uses more phosphates than you think. It’s a type of algae after all.

Surprisingly my coralline is average amount because I have 3 tuxedo urchins in the tank and they munch it back constantly.

 

[vetteguy53081]

This is always a level that creates mystery yet gets the blame when there is algae or other tank issues and phosphate is not limited to but is generally caused by overfeeding, decay and use of tap water and even expired RO cartridges at time. Phosphate is not toxic and it won’t directly harm anything within the tank but will keep algae very happy.
At times , we consider Phosphates above .1 as a high level and begin to combat it when is essence the zooxanthellae within coral are stimulated by phosphate which provides energy for their tissue growth. However if po4 levels are high for an extended period, the zooxanthellae can overpopulate and suddenly you see coral turning brown.
The problem with aiming for po4 levels of .04-.08 is that every tank is different and have different absorption requirements.
A general rule for me is , if I have higher phosphate but dont have algae, keep an eye on it but its likely not causing problems. I do run alternately chemiPure blue and Elite for Phos control.

 

[shootingstar_reef]

High phosphates can and often do cause coral skeletons to cease growing especially in new tanks with only a few corals.

Newer tanks also have nuisance algae that form until coralline comes in. Algae can smother coral quite easily. It can use allelopathy to fight coral. High phosphates in that environment just throws gasoline on the fire.

There is scientific evidence that high phosphate results in the acceleration of growth (Gunn et al., 2012. JEMBE https://www.sciencedirect.com/science/article/pii/S0022098111004588). Acropora, considered one of the more sensitive corals, have spawned in PO4 levels of 0.9 (https://www.frontiersin.org/articles/10.3389/fmars.2022.961106/full). There are plenty of aquarists who don't check, or even have levels above 1 ppm.

So for me, when I came across this information, the prevailing belief in the hobby that "high" phosphates are bad im just not as convinced as i once was. There must be something else that's more important

 

[Fishy888]

There is scientific evidence that high phosphate results in the acceleration of growth (Gunn et al., 2012. JEMBE https://www.sciencedirect.com/science/article/pii/S0022098111004588). Acropora, considered one of the more sensitive corals, have spawned in PO4 levels of 0.9 (https://www.frontiersin.org/articles/10.3389/fmars.2022.961106/full). There are plenty of aquarists who don't check, or even have levels above 1 ppm.

So for me, when I came across this information, the prevailing belief in the hobby that "high" phosphates are bad im just not as convinced as i once was. There must be something else that's more important

The reason one system gets thick nuisance algae at 1 ppm and another gets insane coral growth at another is most likely because there’s enough coral to utilize phosphates and nitrates for that matter. The first tank also lacks the stability of the second tank hence no coralline, which the second tank likely has. I realize not all successful SPS tanks have coralline. Some people don’t want it so their CUC eat it and/or they scrape it off the glass. That theory, though I don’t remember where I read it, is the theory I ascribe to.

 

[sdreef]

I personally wouldn't be concerned about the phosphate level. But if the trend is that phosphate levels are continuing to increase, I'd make an adjustment to your export to maintain your desired phosphate level.

Anecdotal, but in the first year of my system I let phosphates get to over 1.0 ppm. Never have experienced an algae problem in this system, but once my phosphates reached above 0.5 I observed a decline in coraline and eventually some of acros demonstrated some decline. This was around the time TM Pro started having issues as well, so not totally clear it was even related to the phosphates. Unclear, but that's when I decided not to let the phosphates ride any further.

So I wouldn't make the decision based on an algae concern. I would however pay attention to the trend of the phosphate levels in your system and adjust export accordingly. I'd suggest selecting a target level and then work to balance export to maintain as opposed to allowing it to continue to creep up.

 

[Lavey29]

Really good replies, thanks guys. I'm running some phosguard and it's slowly coming down. It's at .34 now. I have to say though the SPS are really showing growth. My LPS seem good but not seeing significant growth is some of them but everything is open and happy looking.

 

[HudsonReefer2.0]

Plus I usually smell a dead snail before I even see it in the tank or sump.

Stop smelling ur snails. That’s just weird…and gross. Just sayin.

 

[Lavey29]

Stop smelling ur snails. That’s just weird…and gross. Just sayin.

That's funny but kind of true. The first thing I do in the morning is smell my tank water. If it smells like a perfect ocean scent I'm happy. If not then I try to find the source of the odor. I smell my sump to but kind of expect some odor there due to the skimmer. I keep a carbon filter on top of my skimmer lid and a fan in the cabinet.

 

[HudsonReefer2.0]

That's funny but kind of true. The first thing I do in the morning is smell my tank water. If it smells like a perfect ocean scent I'm happy. If not then I try to find the source of the odor. I smell my sump to but kind of expect some odor there due to the skimmer. I keep a carbon filter on top of my skimmer lid and a fan in the cabinet.

Yeah I get that. Lol. There is a distinct briney scent to a healthy system. U know it when u have it. Smells like stability. Lol.

 

[Randy Holmes-Farley Verified Community Expert]

So for me, when I came across this information, the prevailing belief in the hobby that "high" phosphates are bad im just not as convinced as i once was. There must be something else that's more important

FWIW, your own reference suggests a downside to high phosphate:

Skeletal density reduction may be due to phosphate binding at the calcifying surface and the creation of a porous and structurally weaker calcium carbonate/calcium phosphate skeleton. Increased phosphate concentrations, often characteristic of eutrophic conditions, caused increased coral growth but also a more brittle skeleton. The latter is likely more susceptible to breakage and damage from other destructive forces (e.g., bioerosion) and makes increased coral growth a poor indicator of reef health.