What is your phosphate management routine?

[Delphinus]

I'll share my own experiences and the reasoning for asking what others do.

I run a tiny little ball of chaeto in an aquaclear lit by 2x9w PC's. This is for a 115g cube so it probably really has a negligible effect on NO3/PO4 pulldown.

I've never been able to get a reading higher than the lowest category on a chemical based test kit. So for some this means "zero" and while others like the D-D/Merck it means "0 to 0.008" (which may as well be zero).

Don't have a lick of GHA in the display, although sometimes I will find some growing in the overflow eggcrate.

Most SPS I have exhibit very poor growth rates (or abnormal mortality rates). I was initially convinced this was due to phosphate but never having been able to establish a significant nonzero reading on any testkit (including the $300 Hanna colorimeter), I started reaching out to other explanations, including pathogens. The story of the last year though is that I am now starting to believe it's not pathogenic in nature ... so I'm coming home to the phosphate theory.

If I could establish that there is a difference made then I would gladly revert back to using GFO. And yet, when I ran GFO in the past, it never made a difference; nor did my brief (6 month) experiment with Zeo.

But so far it sounds like that for those who have noticed a difference with and without GFO, that the difference was enough to be profound, or at least, enough to actually notice a difference. So this is still confusing to me as to whether I may truly have a phosphate buildup or not.

Anyhow thanks all for the comments and thoughts. It is all very interesting to me.

[marie]

Tony, I am pretty sure I have relatively high phosphates...I have cyano and numerous pest algaes trying to poke their noses in where the fish can't reach them but my corals grow like mad,...it would take a lot to convince me your sps problems are because of phosphates

[nlreefguy]

I would also love to hear others' perspective on this. I had a similar problem with growth and survivability with SPS in my previous tanks, and now in my current tank my SPS are thriving and growing despite the fact that as far as I know, I'm not doing anything any differently than in my previous tanks. Still using GFO and carbon, same circulation pattern, exactly same lighting, same water source, etc. So I'm most interested too, Delphinus. Sorry about directing the thread away from the original intent, by the way.

[fishytime]

I run Rowaphos(gfo) in a reactor
Cheato in the fuge
never have tested for phosphate

Phosphate test kits are a waste of money IMO.

[untamed]

My experience is almost identical to yours, Tony....right down to using the colorimetre.

To Marie's point... If you measured for phosphate, I bet you would be surprised. I started testing phosphate and trying to reduce phosphate because I grow a lot of algae and cyano and I'm always told "to get rid of cyano, you have to reduce nitrate and phosphate".

So here's the rub: I've never been able to measure any significant nitrate or phosphate in my system using the best measuring equipment that can be reasonably purchased. So I'm told "that's because all the algae and cyano are using it up before you can measure it".

I run RowaPhos in a TLF and change it out about monthly. I have never been able to determine if that is an adequate schedule or not.

I've been VSV (vodka, sugar, vinegar) dosing for almost two months now and in spite of increasing dosage nothing significant has happened. (I still measure almost zero nitrate and phosphate). Well...my chaeto has basically died so I guess something has happened....but I still have a lot of cyano issues.

[marie]

Originally Posted by untamed

....

So I'm told "that's because all the algae and cyano are using it up before you can measure it".

...

If that's the case then wouldn't the algae and cyano also be removing it before it can affect coral growth and therefore be a non issue?

[marie]

From my understanding, all living organisms uses phosphates to some degree and it follows any food you add to the system will have phosphates bound up in it (whether it's listed on the label or not).
The more animals and plants you have living and growing in your system, the more phosphates get taken out of the water column. Problems arise when there is too much phosphate getting bound up in the coral skeleton that's when it starts to affect tissue growth

....some phosphate good, too much very, very bad

[Lance]

My 90g has been running for 2 years and has a pretty large bio-load. I have never had noticeable PO4 or NO3 readings on either Salifert or Elos kits. SPS grows quite well in this tank and very seldom do I have issue with algae growth.
In the 225g tank however, SPS doesn't do crap. A few pieces do ok and others not so good. I am always having algae issues as well. P04 readings in this tank are undetectable and N03 are about 10 to 15.
Both tanks get 10% water changes bi-weekly, both have refugiums with DSB and large amounts of macro-algae. I have tried Tailored Aquatics Nitrate and Phosphate Destroyer; vodka dosing; and larger water changes on the 225g: with no positive results. SPS continue to struggle and algae growth has not been reduced.
The only difference I can see between the 2 tanks is the rock I used when setting up. The 90g was all live rock, while in the 225g I used a lot of BRS Eco-Rock. Perhaps there is a lot of phosphates bound up in this rock and continues to leach out.