Persistently high Phosphate...big stumper

[forestsofkelp]

I have had persistently high phosphates for the last 3 months. I used to run 0.13-0.18 reliably. Now I run 0.23-0.33 reliably. Over the last 3 months I have reduced feedings 50-57%,, dosed lanthanum (which works), tested my RO water, have not added new rock, have changed my GFO frequently (I use rowaphos) etc etc. I cleaned all my pumps last week and my skimmer is having more output for the last 4 days...now my P is the highest it's been all year. I give each change a week or two to to settle in. No changes

I cannot think of or find a source for the phosphate. My SPS have dulled up and I get more algae on the glass, but so far no other ill effects. I am trying to get it under control as I dont know if will continue creeping up. It's very annoying. I wouldn't be chasing it if my SPS weren't dulling up.

I am stumped to the cause. Has anyone had anything like this before?

Parameters are Alk 9, Ca 489, N 20.1, Phos 0.33, Mag 1430, salinity 1.0265. I test weekly and those are pretty usual number for me, although N will range from 8-20. I feed either Rods food or 2 cubes of Hikari (various types) and NLS pellets several times a day off an auto feeder.

I've read tons of threads so I dont know if there is much to add unless someone has some insight. Part of this is just venting I suppose.

 

[Spare time]

Not sure the cause except possible excess food waste, but I'd just keep gfo going. You are feeding very heavily so having a better clean up scavenging crew might help if you are getting lots of leftovers. Swapping filter socks or whatever mechanical filter daily can help too. Refugiums or algae scrubbers can help too.

 

[forestsofkelp]

Thx. Yeah I might need more CUC. You think it’s too much food? I have 3 tangs, 5 anthias, 2 wrasses in a 180

 

[Spare time]

Thx. Yeah I might need more CUC. You think it’s too much food? I have 3 tangs, 5 anthias, 2 wrasses in a 180

Feeding several times a day is bound to bring a lot of phosphate into the tank. Do you visibly see leftovers when you feed? If so, more hermits, nasaarius, brittle/serpent stats, etc. will help. If not, then maybe consider a refugium or algae scrubber or up the gfo.

 

[Spare time]

PS it can take a while to remove phosphate since it will reach from rocks and sandwhej removed from the water column.

 

[Lavey29]

Those numbers while slightly elevated are not bad. How is the tank responding? Typically your rocks absorb phosphates and reach a saturation point then leach back into the water column hence your numbers go up.

 

[Pistondog]

Do you have a way to verify your test results?
2nd test kit?

 

[forestsofkelp]

Feeding several times a day is bound to bring a lot of phosphate into the tank. Do you visibly see leftovers when you feed? If so, more hermits, nasaarius, brittle/serpent stats, etc. will help. If not, then maybe consider a refugium or algae scrubber or up the gfo.

very few leftovers. Usually everything is gone in a few minutes. I could use more CUC but my team (although small) *appears* to get it all . I increased feeds earlier this year after my anthias school thinned out from what I presumed was not frequent enough feedings and upped it a little, then went back down. Maybe I am seeing the spike from feeds a few months ago.

Those numbers while slightly elevated are not bad. How is the tank responding? Typically your rocks absorb phosphates and reach a saturation point then leach back into the water column hence your numbers go up.

I am getting more algae on my glass, a few patches of algae/cyano (nothing major) and SPS dulled up. It's not terrible. I am concerned that it will get out of control, as I dont have time to deal with that (baby, toddler, demanding . So I am trying to fix it before it even gets close.

Do you have a way to verify your test results?
2nd test kit?

I have the hanna controls and my checker is accurate. Ive also changed vials and reagent packets.

I have a chaeto reactor as well. It used to grow fast, but for about a year has been really slow for no clear reason. Flow is good, light is the same, etc etc.

I think for now I am going to use lanthanum chloride every other day for a week and add a 1/2 container if Rowaphos. If it rises again, I'll swap it for the other half and use lanthum as needed. In the meantime I'll get some more CUC and also use a different brand of GFO. I have a hunch my old brand of GFO might work better. I checked my logs and my phos rose 3 months after switching to rowaphos.

Any other advice is welcome. It's annoying as heck when there are little things like this I cant figure out. I know there's only a few things that raise phosphate but none of them seem to clearly be it. It's probably feeding or one of my foods. Weirdly Hikari and NLS aren't known to be high in phos AFAIK...

 

[Spare time]

You could try some bacterial mix too to help compete with the algae. The idea of bacterial products such as waste away is that they add bacteria to the water column that is normally skimmed out (i.e. adding competition back into the tank). Just something cheap you can try as a why not.


As for the chaeto, maybe try dosing chaetogro.


More snails and such should also help with the algae.

 

[forestsofkelp]

I REALLY appreciate everyone's advice.

I decreased pellet feeds by another 50%. I started skipping some frozen food feeds
I used lanthum chloride daily for 2 days in a row
I rinsed my chaeto
This finally dropped my Phos from 0.36 to 0.18 in 2 days
Then I added 500g of rowaphos to my reactors.
next day my phos was 0.05
day after that it was 0.1
today (2-3 days later) it was 0.06

so the culprit I think was really overfeeding, but adding 2.5x the amount of rowaphos I usually add in combo with cutting feeds really took it down.

I am added 8 more fish (increasing my fish load by 1/3) more CUC, and increasing feeds only a little to compensate for the new fish. I think it will really help and the problem has solved.

I also think 1/2 kg of rowaphos helped too lol

I appreciate the advice I think I was going a little too slow and the extra fish/CUC were great ideas. I wanted to make sure I wasnt missing anything before I jacked up my removal methods.

Next up is an iron test to make sure my chaeto is well supplied.

Merry christmas and happy holidays

 

[Bioloco (EasyReefs)]

I have had persistently high phosphates for the last 3 months. I used to run 0.13-0.18 reliably. Now I run 0.23-0.33 reliably. Over the last 3 months I have reduced feedings 50-57%,, dosed lanthanum (which works), tested my RO water, have not added new rock, have changed my GFO frequently (I use rowaphos) etc etc. I cleaned all my pumps last week and my skimmer is having more output for the last 4 days...now my P is the highest it's been all year. I give each change a week or two to to settle in. No changes

I cannot think of or find a source for the phosphate. My SPS have dulled up and I get more algae on the glass, but so far no other ill effects. I am trying to get it under control as I dont know if will continue creeping up. It's very annoying. I wouldn't be chasing it if my SPS weren't dulling up.

I am stumped to the cause. Has anyone had anything like this before?

Parameters are Alk 9, Ca 489, N 20.1, Phos 0.33, Mag 1430, salinity 1.0265. I test weekly and those are pretty usual number for me, although N will range from 8-20. I feed either Rods food or 2 cubes of Hikari (various types) and NLS pellets several times a day off an auto feeder.

I've read tons of threads so I dont know if there is much to add unless someone has some insight. Part of this is just venting I suppose.

Hi buddy! Have you coral sand in the aquarium? Has you think in the posibility of a fosfate reservoid? Some types of coral sand can retain and become saturated with phosphate. When the interstitial pH of that sand becomes acidic, it begins to release it. It's a fenomenon very commun in aquariums with this tipes of sand.

 

[mangolove]

For the cheato : Iron / trace elements

Aquaforest Phosfate minus in a media bag and maybe use some zeomix aswell

Aquaforest nitraphos minus instead of what ur dosing now to lower nitrates

 

[jda]

Your rock and sand have bound a bunch of phosphate. It binds with equilibrium to the amount in the water column. If they water column level rises, then the rock binds more. If the water column level lowers, then the rock unbinds.

This is not an absorb and leach type of thing... it is a bind and unbind. There are rules and stuff with binding.

You just have to keep removing the po4 from the water column and the rock/sand will unbind and you will eventually get lower results. Go slow. The rock can unbind in a day or less, so you don't want the water column level to drop to nothing and then spike back up again.

As said, .2X is not all that bad for some inhabitants. It can be bad for others. However, you know which way this is going, so you will need to do something eventually.

 

[Nano_Man]

L chloride will reduce phosphate but read Randys https://www.reef2reef.com/threads/diy-lanthanum-dosing.969669/post-11934451

 

[Bioloco (EasyReefs)]

This is not an absorb and leach type of thing... it is a bind and unbind. There are rules and stuff with binding

Hi!

Those balances depend on the phosphate concentration in the water, material saturation and pH environment. If inside the sand (or one zone, for example under the rocks) there are a bad ionic exchange the pH can down in the interstitial water because the nitrification and decomposition metabolism. This releases extra adsorbed phosphate and dissolved some of sand tha is calcium phosphate in some proportion. The result is an "inexplicable" and slow increase of measure phosphate levels that the animal feeding can't justified.

The solution is like you said and I advise too some sand siphoning when waters changes. I don't like the sand siphoning, aren't the best for the sand animals but in these cases it had demonstrated to me to be a great helpfull.