ser_renely
Active member
I know I have them, but how come they show up as 0 when tested for them? do all test kits do this?
I use API
I use API
why do phosphates not show up on testing?
- Thread starter ser_renely
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StupidsReef
Premium Member
Because there are many forms of it.
Anthony Cailfo would best answer this question for you.
Try advance forums for this. I'm not an expert on it but can point you to the right forum.
Anthony Cailfo would best answer this question for you.
Try advance forums for this. I'm not an expert on it but can point you to the right forum.
The tests are capable of detecting phosphate that's floating around in the water, but phosphate is a very sneaky chemical: it's rarely in the water for long---it runs over and locks itself into algae, or it dives into rock and sand and bonds with that. So the test looks for it, but there's none in the water---there's plenty in the tank---but there's none in the water. Algae has it all; and it will slowly creep out of the rock and sand, particularly when algae spores light there and look for phosphate to help them grow---bingo! there it is, which is why white bare rock in most any tank immediately turns green with algae.
That's also why it's hard to remove: you can run a phos-reactor until you're blue in the face and still have a tank green with algae, because the algae is so happy it's not turning loose of any phosphate at all. Only by turning the lights out and discouraging some algae to death can you make it shed it into the water where, with luck, the phos-reactor will snatch it before the rock does. THat's how the reactor works: it has something (granulated iron oxide) that phosphate will stick to faster than it sticks to just plain rock. You can get an animal to eat the algae and poo it into the water to be broken down, and that's another chance for the reactor to get it.
Or a fuge---which does it by coddling algae that's always lit, so it gets the phosphate first. Eventually what's in your tank starves to death.
That's also why it's hard to remove: you can run a phos-reactor until you're blue in the face and still have a tank green with algae, because the algae is so happy it's not turning loose of any phosphate at all. Only by turning the lights out and discouraging some algae to death can you make it shed it into the water where, with luck, the phos-reactor will snatch it before the rock does. THat's how the reactor works: it has something (granulated iron oxide) that phosphate will stick to faster than it sticks to just plain rock. You can get an animal to eat the algae and poo it into the water to be broken down, and that's another chance for the reactor to get it.
Or a fuge---which does it by coddling algae that's always lit, so it gets the phosphate first. Eventually what's in your tank starves to death.
ser_renely
Active member
thanks guys 
fatdaddy
New member
Try testing your tap water. It probably has phosphate in it.
When I was fresh in the hobby, I bought distilled water from walmart for makeup water. It had 3ppm phosphate in it.
You're probably doing well with 0 phosphate. But, you could still have a high-nutrient tank, like sk8tr pointed out.
If you have lots of algae, then use a filter sock when you scrub the tank to catch the debris. Reduce feedings, etc.
When I was fresh in the hobby, I bought distilled water from walmart for makeup water. It had 3ppm phosphate in it.
You're probably doing well with 0 phosphate. But, you could still have a high-nutrient tank, like sk8tr pointed out.
If you have lots of algae, then use a filter sock when you scrub the tank to catch the debris. Reduce feedings, etc.
uscharalph
New member
Are you testing you display tank water or the water you are adding into the tank?
+1 with sk8r. The best way to keep phosphate out of your tank is not introducing it in the beginning. Rinse frozen food, make sure your water is RO/DI, etc. Once it is in the rock, it is hard to remove. GFO reactors are a start. I test mine with a Hanna photometer and I try to keep it from 0.02 - 0.04
I've never owned one. I look at the algae and know I have phosphate. Since nothing but algae likes it, I start working to get rid of it---at least in the display.
Here's the other part I didn't mention: if it's not leaving the algae it's not annoying the corals---currently. Of course, if you have a lot of algae, the algae starts crowding and shading the corals and messing up the water, which they don't like. So algae (therefore phosphate) belongs in the fuge, where it's perfectly safe from bothering my corals. Periodically I divvy off half of it and trade it in at my lfs for credit, which gives me a lot of moral satisfaction. I hate tank algae.
Here's the other part I didn't mention: if it's not leaving the algae it's not annoying the corals---currently. Of course, if you have a lot of algae, the algae starts crowding and shading the corals and messing up the water, which they don't like. So algae (therefore phosphate) belongs in the fuge, where it's perfectly safe from bothering my corals. Periodically I divvy off half of it and trade it in at my lfs for credit, which gives me a lot of moral satisfaction. I hate tank algae.
Check out Randy Holmes Farley's article on phosphate. You can find a list of his articles at the begginning of the reef chemistry forum.
There are more than one kind of phosphate.
Organic phosphate is not measured by test kits. It's not detectable since it is bound to organic material which may or may not be exported by your skimmer or carbon or it may breakdown and provide inorganic phosphate to feed nuisance algae.
Inorganic phosphate (orthophosphate ) is measured by kits. But in my experience, these kits are very difficult to read with precision at the low levels we wan't to manage,particulary in an sps tank.I have used the salifert and api kits and really can't discern the precise level. For this reason I have ordered a colorimeter (photometer) and should have saved the money I spent on kits.Even if I can measure phosphate more accurately ,opportunistic algae might be grabbing it out of the water very quickly giving a reading after they have consumed some of it.
Control for reduction is the same wether you measure it or not.Aggressive skimming, no overfeding, rinsed frozen food, macroalgae in a refugium,good flow to work against detrius build up maintenance of the substrate and no mechanical filtration unless it is cleaned at least once a week are some of the things that require ongoing attention.A remover such as granulated ferric oxide or poly padcan also be used.
There are more than one kind of phosphate.
Organic phosphate is not measured by test kits. It's not detectable since it is bound to organic material which may or may not be exported by your skimmer or carbon or it may breakdown and provide inorganic phosphate to feed nuisance algae.
Inorganic phosphate (orthophosphate ) is measured by kits. But in my experience, these kits are very difficult to read with precision at the low levels we wan't to manage,particulary in an sps tank.I have used the salifert and api kits and really can't discern the precise level. For this reason I have ordered a colorimeter (photometer) and should have saved the money I spent on kits.Even if I can measure phosphate more accurately ,opportunistic algae might be grabbing it out of the water very quickly giving a reading after they have consumed some of it.
Control for reduction is the same wether you measure it or not.Aggressive skimming, no overfeding, rinsed frozen food, macroalgae in a refugium,good flow to work against detrius build up maintenance of the substrate and no mechanical filtration unless it is cleaned at least once a week are some of the things that require ongoing attention.A remover such as granulated ferric oxide or poly padcan also be used.
