Undetectable Phosphates???

[baslewprime]

my parameters
40g cube with alot of flow( 4 months old)
GAC and Skimmer
alk 11.8
magnesium 1200
calcium 360
nitrates 2ppm
phosphate undetectable using hanna checker PHOSPHORUS ULR
IO salt
gravity 1.026

What could be the reason my phosphates are undetectable?

and what should i do? my rocks growing hair algae and green dots

 

[KJ]

What could be the reason my phosphates are undetectable?

You algea consuming PO4 lot faster.

 

[Deiblerj]

GAC isn’t helping either

 

[baslewprime]

what should i do?

 

[Deiblerj]

Take out the GAC and check it in a few days to see if there is any change. If not you could start dosing. I think once you remove your carbon you’ll see your phosphates start to creep up

 

[Deiblerj]

I had the same issue. I was running carbon in my HoB filter on my 40 breeder. Took it out and replaced it with a second sponage. Phosphates started to go up. Takes a while to balance them espiecally if you start getting some algae growth because that will lower your phosphates as well

 

[baslewprime]

but GHA will grow alot faster right?

high phosphate = algae issue

low phosphate = non algae but corals thrive? or chance to grow another bacteria like (cyano, dinoflagellates)

 

[Randy Holmes-Farley Verified Community Expert]

Take out the GAC and check it in a few days to see if there is any change. If not you could start dosing. I think once you remove your carbon you’ll see your phosphates start to creep up

I don't think GAC will bind any inorganic phosphate from seawater. It might help phosphate decline by binding some organics that contain P and exporting them before breaking down, but in general, it's not a big way for P export.

 

[Randy Holmes-Farley Verified Community Expert]

what should i do?

I'm not sure you need to do anything about it. I likely would not as long as algae is growing significantly (and the "algae" is not brown dinos).

If there are corals in the tank, I'd boost calcium to 420 ppm and maybe magnesium, although the mix likely has plenty and the 1200 is likely lower than the real value if the salinity is correct.

Have you measured nitrate?

 

[baslewprime]

I'm not sure you need to do anything about it. I likely would not as long as algae is growing significantly (and the "algae" is not brown dinos).

If there are corals in the tank, I'd boost calcium to 420 ppm and maybe magnesium, although the mix likely has plenty and the 1200 is likely lower than the real value if the salinity is correct.

Have you measured nitrate?

skimmer turn it off for a week so that nitrates rise to 2ppm

 

[saltyfilmfolks]

IMO . Don’t sweat it unless you are having issues.
If it was a dry rock tank you likely never had much Po4.
If you have algae and whatnot , it’s not the Po4 and no3. Kinda.
Low nutrients will discourage the growth of bad Algaes. Not stop them. Horrible myth.
In a new tank , watch the growth of algaes. As it begins , add clean up crew. Get a tooth brush.
With normal feedings the Po4 will rise , as well as the no3.

If you are really worried about it , you can dose both no3 and Po4. But I don’t see the point if that really.
Too many easy ways around it

 

[baslewprime]

I'm not sure you need to do anything about it. I likely would not as long as algae is growing significantly (and the "algae" is not brown dinos).

If there are corals in the tank, I'd boost calcium to 420 ppm and maybe magnesium, although the mix likely has plenty and the 1200 is likely lower than the real value if the salinity is correct.

Have you measured nitrate?

im using red sea test kit for everthing except phosphate

 

[baslewprime]

IMO . Don’t sweat it unless you are having issues.
If it was a dry rock tank you likely never had much Po4.
If you have algae and whatnot , it’s not the Po4 and no3. Kinda.
Low nutrients will discourage the growth of bad Algaes. Not stop them. Horrible myth.
In a new tank , watch the growth of algaes. As it begins , add clean up crew. Get a tooth brush.
With normal feedings the Po4 will rise , as well as the no3.

If you are really worried about it , you can dose both no3 and Po4. But I don’t see the point if that really.
Too many easy ways around it

so about that myth Is it good to not have phosphates?

and thank you so much!

 

[Randy Holmes-Farley Verified Community Expert]

so about that myth Is it good to not have phosphates?

and thank you so much!

Not sure which way you mean there's a myth, but having no phosphate is bad. Likely much worse than having too much.

But many kits cannot read low enough to say if it is too low or not.

 

[Randy Holmes-Farley Verified Community Expert]

im using red sea test kit for everthing except phosphate

The Red Sea magnesium kit, when used by ordinary reefers, is very prone to wrong values for reasons that I do not understand.

 

[saltyfilmfolks]

so about that myth Is it good to not have phosphates?

and thank you so much!

Not sure which way you mean there's a myth, but having no phosphate is bad. Likely much worse than having too much.

But many kits cannot read low enough to say if it is too low or not.

Many many many reefers I speak to are “battling Po4 “ from day one , even before there’s coral or fish in the tank because phosphates are “bad” and having zeros in some cases are a source of pride.
Add that to hobby grade test inaccuracies and it becomes a fools errand in most cases.

For quite some time I advised a lot folks with newer struggling coral tanks to look at weekly water changes like dosing and export. If the nutrients are low and the minerals are ok , why do it?
Observe the tank , it’s specific to your tank.

Without mud , there is no lotus.

 

[baslewprime]

thank you guys [emoji16][emoji16][emoji106]

 

[Randy Holmes-Farley Verified Community Expert]

You're welcome.

Happy Reefing.