Phosphates: The last frontier

[Clownreef]

Man.. It has been a battle.. NoPhos, GFO, Phosban, Phosdelete, Phosnever, Rowaphos, GoodbyePhosphates, Phosphates E.. Fuge, water changes, and I can't for the life of me get them under 0.13. Ive been reefing for 20 years so I understand the nuances of water chemistry. Ive successful kept SPS for a long time but are phosphates the impossible parameter? I know some reefers have to ADD phosphates and how I wish that was my issue. Are the causes the sludge sitting on my overflow box? the little detritus in the sump? My rocks are old and covered in purple, I have a shallow sand bed that ive had for years...

I....just....dont....know.

 

[Randy Holmes-Farley Verified Community Expert]

lol

Declare victory and relax.

My TARGET recommendation for phosphate is 0.06 to 0.3 ppm. There's is no clear reason to try to get phosphate below 0.13 ppm. :)

This has more, including justifications for the recommendations:

https://www.reef2reef.com/ams/randy’s-thoughts-on-nutrient-target-ranges.1087/
from it:

4. What targets seem reasonable? Of course, that depends on all the other factors at play, such as types of corals, availability of ammonia, particulate foods, etc. However, for a mature mixed reef, this would be how I personally would run it:

• Let nitrate float between 5 ppm and 50 ppm. I’d use gentle export in this range, such as growing macroalgae.
• Above 50 ppm, I’d begin to focus more on reducing it, by organic carbon dosing, turf or macroalgae, etc.
• Below 5 ppm, I’d begin to dose ammonia or feed more. The target level might drop lower if dosing ammonia, just like the heavy in/heavy out scenario where nitrate may not be as needed.
• Let phosphate float between about 0.06 ppm and 0.3 ppm. This range is higher than I’ve recommended in the past. I’d use gentle export in this range, such as growing macroalgae.
• Above about 0.3 ppm, I’d begin to focus more on reducing it, by turf or macroalgae, or a binder such as GFO or lanthanum (has its own risks to tangs). If a binder: GO SLOW. Turf and macroalgae will typically be slow enough.
• Below 0.06 ppm, I’d begin to dose sodium phosphate or feed more to get the level up.

 

[Bear22]

Agreed. This is the one parameter that seems to be the the greatest challenge. I have to dose NO3 in my system while having to implement control measures for PO4 (water changes and Rowaphos). I could dose lanthanum, but that just opens up more cans of worms (headaches) that I am not willing to bring about.

 

[X-37B]

.13 is a good number. What po4 reducers are you currently running to keep it at .13?
The sludge wont matter unless you stir it up.
I feed heavy in my 150 and carbon dose to keep no3 around 5. I use phosphate minus because you dont rinse it. For my system it works better than standard gfo.
Po4 gets to .2 and I add 1/2 cup of P- and it drops to .1.
If your syatem looks good no need to change anything.
Any pics?

 

[rtparty]

Testing error, food being fed, phosphates released from rocks. Could be many things but I’d 100% stop chasing it that hard

 

[Clownreef]

.13 is a good number. What po4 reducers are you currently running to keep it at .13?
The sludge wont matter unless you stir it up.
I feed heavy in my 150 and carbon dose to keep no3 around 5. I use phosphate minus because you dont rinse it. For my system it works better than standard gfo.
Po4 gets to .2 and I add 1/2 cup of P- and it drops to .1.
If your syatem looks good no need to change anything.
Any pics?

Thanks everyone. Thanks Randy. Makes a lot of sense.

My No3 stays consistently at 3. Phosphates are the ones im always having trouble lowering. I dont overfeed by any stretch of the word. The fish are pretty healthy and eat a myriad of frozen food (eggs, brine, etc) with a healthy dose of seaweed every morning. I run a reactor with either phosban or rowaphos, a bio pellet reactor, a great skimmer (Bubble King 200 V12. My fuge has cheato.

Here's a bad iPhone picture I just took.

 

[Clownreef]

This was in 2021. We had an insane freeze in Texas that year and unfortunately I had no way to get RO water and used water from those dispensers on the street. I knew the risk I was taking but I was desperate. I lost all of my corals. Im a Chef. I own a restaurant and have slightly neglected by duties so I haven't added any SPS since. Im getting my parameters in check to stuff it back again (thanks Adam at @Battlecorals !). Im obsessed with my water chemistry at the moment.