Need to cut Phosphates in Half

[TheDashCave]

Question: Phosphates currently at 30ppb/.0092, skimmer recently went back online a week ago. Weekly water changes at 20%.

Increase volume of water changes per week? Add GFO? Do nothing and see what the skimmer does left on 24/7? Add my ATS back to the tank?


How I got here:

I sent out an ICP test today. Leading up to the test, I maintained a maintenance schedule that is easy for me to do and one that I stick to. No extra work outside of things I manage every week on the tank. With water change day being tomorrow I took the sample today figuring this is when the tank is probably at its worse during the course of the week.

Out of curiosity I ran some baseline tests of my own.

Hanna ALK: 9.1
Red Sea Cal: 435
Red Sea MG: 1500
Hanna ULR: 30/.092

The thing that stuck out was my Phosphates being high. Previously I had struggled with having little to no phosphate. So I took my skimmer off line and bought into the hype and started dosing Brightwell Amino's. My sps were pale already due to negligence earlier this year, figured what the heck. I can say I've see a positive effect on the sps in the tank over the course of the past month.

No major algae outbreak in the tank, the sand could be cleaner. Sps look happy with good PE.

Soooo...

Increase volume of water changes per week? Add GFO? Do nothing and see what the skimmer does left on 24/7? Add my ATS back to the tank?


What I don't want to do is change my feeding habits at the moment, fish are plump and happy.

 

[ZaneTer]

I’m curious why you feel you need to halve your PO4 when you have noticed that your corals are looking great?
Personally I would just leave it all alone...

 

[BayouReefer]

I agree .01 is more than acceptable. 0 PO4, 0 NO3 increases your chance of getting Dino’s

 

[TheDashCave]

Not to chase numbers, but isn't a mark around .003 preferred for coloration and health?

I want to assume the worst and that is I'm catching them on their way up. I've never purposely kept a super clean system, but I'd rather nip this in the bud.

In general the tank looks healthy, I am seeing some additional green and lack of "true" color on a couple of my sps. Quick search yielded that phosphates could lead to a more green tinge on sps? Totally different topic and one I have not researched enough. Figured if there is a correlation it would now point to Phosphate, thus remove/reduce asap.

 

[Righteous]

0.01ppm to 0.03ppm is usually considered the sweet spot (so at 30ppb or 0.03ppm you are already there). But people report success with even higher levels. Lower than 0.01 is hard to achieve if you're feeding enough, and many people consider that a danger zone for dinoflagellates.

 

[BayouReefer]

I believe your adding an extra 0 should .02 to .03 your number that you put up was .0092 which is below a .01 I now I see you also put a reading of .092 which makes a huge difference your decimal point keeps changing

 

[W1ngz]

30ppb is 0.092, or just round up to 0.1.

This is outside the 'recommended' range, but still largely acceptable - especially if your corals are doing well and there's no significant algae growth. I would just keep an eye on it and look for a trend over several days or weeks. Is it rising, falling or stable at that number? Mine wanders between 0.08 and 0.13 ppm, and is consistently in that range. Since it's consistent, I don't consider it a problem.

If you really want it lower, add some GFO and keep an eye on the levels daily until it comes down to where you decide it needs to be. Stop the GFO and see if it stays stable.

This chart may help with the rogue decimal point problem.

 

[MTBake]

I would do nothing. Don't go chasing numbers if the tank is happy

 

[Righteous]

30ppb is 0.092, or just round up to 0.1.

Phosphates currently at 30ppb/.0092

To clarify, the OP stated "phospates" where at 30ppb, then followed up saying he thought ".003" was preferred.

The issue is confusion between Phosphorus (P) and Phosphate (PO4) readings.

If you're using the Hanna 736, that reports Phosphorus (P) in the ppb range. You can use the chart posted by W1ngz to convert to Phosphate (PO4) measurement, which is what most people talk about.

So if you're talking Phosphate levels, 0.01-0.03ppm is the "sweet spot" which reads as ~3-10ppb Phosphorus on a Hanna 736 checker.

If you're getting a reading of 30ppb Phosphorus (P), then that is getting a bit high, but not any emergency. GFO will bring that down quickly. Going slow with GFO is always advised.

 

[TheDashCave]

Sorry everyone I wrote two different numbers in the OP.

The phosphorus is 30ppb = .092 not .0092

If this level isn’t so high would it be safer to manage with WC or does this warrant the use of GFO?

 

[BeejReef]

To add to the chorus, I'd do nothing for two weeks and test again. If it's still in that .07-.1 range, I'd say you're crazy if you touch it. That's pretty low and stable.

If it's continuing to rise, then look into options. Right now, you're dealing with a single point of reference. Almost all phosphate removal products have the potential to quickly strip phosphate to near 0 which is near universally accepted as bad. .09 P is generally regarded as a touch high, but not of any real concern. I'd wait to see a trend before adjusting. If that trend was "stability a touch higher than I like," I'd learn to like it.. lol

 

[Righteous]

I prefer GFO... i think it's more cost effective depending on your tank size. Doing a 50% water change is going to only get you down to 15ppb, which isn't bad... but then will start to go up again as you feed... also sometimes Phosphate syncs leach back into the water, etc.

GFO is easy, and will remove phosphate more efficiently and on a continual basis. When you start, the GFO will get depleted quicker. Just keep checking the water to see when it stops dropping. 30ppb water will deplete GFO 3x faster than 10ppb water, and so on. So when you get down to 3ppb or so, your GFO can last quite a while.

I've personally seen great color and growth benefits for SPS, especially Acros keeping in the 3-10ppb range. I notice slower growth and loss of color as Phosphates rise. With LPS and other more hardy corals, the benefits are mostly in the control of nuisance algae, and depending on your herbivore livestock, it may not be a problem at all.

 

[Righteous]

Almost all phosphate removal products have the potential to quickly strip phosphate to near 0 which is near universally accepted as bad. .09 P is generally regarded as a touch high, but not of any real concern. I'd wait to see a trend before adjusting. If that trend was "stability a touch higher than I like," I'd learn to like it.. lol

Good advice, going slow is always the best advice. Even if you have some SPS you want better color on, start with small changes. Stable Phosphate is going to be better than swings up and down.

If you do go the GFO route, BRS has a handy calculator. You can start with 1/4 to 1/2 recommended, and go from there.

Aquarium and Reef Calculators - Bulk Reef Supply

Bulk Reef Supply - Saltwater Aquarium Supplies for Reef Tanks

www.bulkreefsupply.com

 

[TheDashCave]

100% correct, only a single point of reference.

With stability being key and, trying to manage all these variables does this sound like a decent plan of action:

- 20% water change today (per schedule)
- Test next again next week (Wed, Oct 9th night before WC)
- Leave skimmer on 24/7 this entire week
- Feed per usual and dose amino per usual

Or is the 30ppb too close to the edge to give it a week to test and take other measures (GFO)?

I do have five mid-high end frags coming in from @AquaSD tomorrow.