PO4 help!

bklynreef · Nov 3, 2016

renato120 said:
I just checked my tank for Po4, and I got 0.39
How bad is it? I Have some cyano bacteria on my sand bed. I run GFO for 4 months.
Nitrate is 20ppm

renato120 said:
Po4 is going down! Just checked and it reads 0.03
I will be changing every two weeks instead of every month.

Wait a Second! I have the same moniter and your results are way off! or you either changed the majority of your water or Overdosed on GFO to the extreme! If thos numbers are right yhen your corals would be shocked and your Alk would spike. Could have been the first test the glass vial was foggy or something happened. I would have checked a second time after that .39 reading.
Tuesday 0.39
Thursday .03
If your an SPS tank then i would keep PO4 between .03 and .06. softies like it dirty and lps also not as clean as sps.
Water changes would be number 1
GFO every month should be enough since GFO can stunt the corals growth and color.
I would feed your fish every other day and only feed as much as you see them eating would letting it drop to the floor or go down the overflow if its a floating food
btw that moniter was the best investment i ever made along with my digital refractometer. Accuracy is #1 and theres no mistake usually on these two milwalkee products

reeferfoxx · Nov 3, 2016

bklynreef said:
Wait a Second! I have the same moniter and your results are way off! or you either changed the majority of your water or Overdosed on GFO to the extreme! If thos numbers are right yhen your corals would be shocked and your Alk would spike. Could have been the first test the glass vial was foggy or something happened. I would have checked a second time after that .39 reading.
Tuesday 0.39
Thursday .03
If your an SPS tank then i would keep PO4 between .03 and .06. softies like it dirty and lps also not as clean as sps.
Water changes would be number 1
GFO every month should be enough since GFO can stunt the corals growth and color.
I would feed your fish every other day and only feed as much as you see them eating would letting it drop to the floor or go down the overflow if its a floating food
btw that moniter was the best investment i ever made along with my digital refractometer. Accuracy is #1 and theres no mistake usually on these two milwalkee products

I'm not familiar with this brand of meter but seems like the readings are legit. I will say though that water changes don't do much for po4. Mainly because po4 is gets absorbed by rocks and can bind to sand. That said, phosphates will continually leach despite water change intervention.

renato120 · Nov 3, 2016

reeferfoxx said:
Nice work! I hope everything else has been staying stable?

Nitrates still high! Im feeding less now. Cyano still there! I hope it will be gone soon.

renato120 · Nov 3, 2016

bklynreef said:
Wait a Second! I have the same moniter and your results are way off! or you either changed the majority of your water or Overdosed on GFO to the extreme! If thos numbers are right yhen your corals would be shocked and your Alk would spike. Could have been the first test the glass vial was foggy or something happened. I would have checked a second time after that .39 reading.
Tuesday 0.39
Thursday .03
If your an SPS tank then i would keep PO4 between .03 and .06. softies like it dirty and lps also not as clean as sps.
Water changes would be number 1
GFO every month should be enough since GFO can stunt the corals growth and color.
I would feed your fish every other day and only feed as much as you see them eating would letting it drop to the floor or go down the overflow if its a floating food
btw that moniter was the best investment i ever made along with my digital refractometer. Accuracy is #1 and theres no mistake usually on these two milwalkee products

The glass was not foggy at all. I did not check it twice. But usually when I do it reads the same. The reason it went down like this could be that the gfo was a month old. I was measuring a half cup. This time I did one cup. I have about 140g total water volume.

bklynreef · Nov 3, 2016

reeferfoxx said:
I'm not familiar with this brand of meter but seems like the readings are legit. I will say though that water changes don't do much for po4. Mainly because po4 is gets absorbed by rocks and can bind to sand. That said, phosphates will continually leach despite water change intervention.

You are correct as the live rock absorbs PO4 but changing out water will do alot more than leaving the same water with high phosphates in there. Clean water equals quicker results along with less feeding and GFO

renato120 · Nov 3, 2016

I just check ALK, and it reads 10. Nothing changed.

bklynreef · Nov 3, 2016

bringing down the PO4 that fast in two days would bleach LPS and SPS. yours is a softy tank?

reeferfoxx · Nov 3, 2016

bklynreef said:
You are correct as the live rock absorbs PO4 but changing out water will do alot more than leaving the same water with high phosphates in there. Clean water equals quicker results along with less feeding and GFO

If the rock is leaching po4 and you perform a 30% water change on a 140 gallon system, you will only reduce 30% of phosphates in the water column. The next day your phosphates will increase again. Water changes are great for nitrate reduction just not phosphates. GFO is the best form of po4 reduction.

renato120 · Nov 3, 2016

bklynreef said:
bringing down the PO4 that fast in two days would bleach LPS and SPS. yours is a softy tank?

Mixed reef! Everything....
All my sps's are on the right top rock.

ksc · Nov 3, 2016

Looks like you got a bad reading. There is no way one cup of gfo would lower your po4 that much. Water changes work just as well as gfo, I like a combination of both.

reeferfoxx · Nov 3, 2016

ksc said:
Looks like you got a bad reading. There is no way one cup of gfo would lower your po4 that much. Water changes work just as well as gfo, I like a combination of both.

Explain how water changes work just as well as GFO?

ksc · Nov 3, 2016

If your water contains .1 po4 and you change 50%, your water (assuming 0 po4 in the new water) will now contain .05. If your water contains .1 po4, and 1 cup of gfo will reduce it by .05, your water will read .05 after that one cup is exhausted.

mcarroll · Nov 3, 2016

Diesel said:
What ever you do, do it slow.
Back off on the food for the fish as well.
Feeding fish is the leading cause of high Po4 and No3

You can say that again!

Especially the first and the last part!

reeferfoxx · Nov 3, 2016

ksc said:
If your water contains .1 po4 and you change 50%, your water (assuming 0 po4 in the new water) will now contain .05.

Correct. Once the rock or calcium carbonate reaches its balance or equilibrates, causing po4 to leach, your 0.05 will raise. After you feed, your po4 will raise.

ksc said:
and 1 cup of gfo will reduce it by .05

This is incorrect. I'm not sure how you can say 1 cup equals 0.05 reduction? How long would it take?

50% water changes a day would equal to GFO performance. Give or take.

Phosban suggests 1 gram per gallon. If 1 cup equals 340g of dry goods(example) than technically he used enough for 340 gallons of water. That's 2.4 times the amount of effective GFO.

Sabellafella · Nov 3, 2016

ksc said:
If your water contains .1 po4 and you change 50%, your water (assuming 0 po4 in the new water) will now contain .05. If your water contains .1 po4, and 1 cup of gfo will reduce it by .05, your water will read .05 after that one cup is exhausted.

Where did you find 1 cup of gfo reduces .05 p04? I use 1 tablespoon in my 120, anymore then that my corals will bleach. My 30 gallon nano i use a half of cup, and it barely keeps my p04 stable. btw I use rowa

renato120 · Nov 3, 2016

Sabellafella said:
Where did you find 1 cup of gfo reduces .05 p04? I use 1 tablespoon in my 120, anymore then that my corals will bleach. My 30 gallon nano i use a half of cup, and it barely keeps my p04 stable. btw I use rowa

Oh great! All I need now is my sps to bleach. I had a half cup there before. Been running it like this for a few months... Tuesday I changed to one cup....

ksc · Nov 3, 2016

I was using hypothetical numbers. Different gfo's have different capacities. All manufacturer's "suggest" certain amounts, I've never seen one actually state solid numbers. Nothing I wrote was "incorrect", as a matter of fact this is incorrect,
"Water changes are great for nitrate reduction just not phosphates. GFO is the best form of po4 reduction."

renato120 · Nov 3, 2016

Can I take some out, or its too late?

reeferfoxx · Nov 3, 2016

ksc said:
Nothing I wrote was "incorrect", as a matter of fact this is incorrect,
"Water changes are great for nitrate reduction just not phosphates. GFO is the best form of po4 reduction."

Actually, this is correct.

Sabellafella · Nov 3, 2016

renato120 said:
Oh great! All I need now is my sps to bleach. I had a half cup there before. Been running it like this for a few months... Tuesday I changed to one cup....

.3 to .03 is a large jump, id just test p04 with the instrument twice a day just to make sure it doesnt run to 0. Every tank is different, i wouldnt even run rowa in my red sea tank, a tablespoon is good enuff for me. My nano needs tons of rowa for unknown reasons. Maybe its the rock, not sure. The thing with gfo, you have to find your tanks "medium". Takes alot of testing, alot of patients, alot of gfo lol but its like dosing, you have to find the exact amount to work good mixed into your feeding+maitnence regiem