Help High ORP and Phosphate

[Buganddoug]

I have a 180 gallon reef tank that I have now for over 17 years. So I got some Instant Ocean Brine Shrimp Gel Food from my clubs Frag swap. After a couple of weeks of feeding this to my tank. I notice some brown algae on my glass and sand bed and my ORP is up abit. My ORP is normally around 250-275 I have been doing ORP readings on my RKE for around two years now.
Okay So I do a water change and my ORP goes from 325 back two 260.
Now my glass on my tank is being cleaned twice a day. In the past I might of done that twice a week. So I buy a Hanna Phosphate meter and my Phosphate is 1.80 Now for the first time I am using Brightwells FerroxiPhos-G GFO. My Phosphate and are coming down. My SPS looking so much better and the algae is all most gone. So I had to pick up Kent Carbon (the recall carbon) because the LFS was out of the carbon I use. My Phosphate is coming down slowly and my ORP is climbing over 600. I have lost 4 tangs now and all my SPS are dead. Now I think this is because of the Dam Kent Carbon.
Why is my ORP up so High and if I do a water change the ORP will come down to about 360 and the next day it is at 500.

I use IO salt. Just this month alone I have gone through a 200 gallon box of salt
This has all started at the end of January

My tank numbers as of today
temp 78.2
salinity 1.026
ORP 495
PH 8.22
KH 8.9
Calcium 440
Magnesium 1340
Phosphate .52

 

[Randy Holmes-Farley]

Without ozone or other oxidizers, ORP is never too high and never is there any concern about it going up. Most often that is a measurement issue, say from a dirty probe or algae growing on it.

That said, I'm not really sure what the problem was with the Kent recall carbon and if that might somehow mess with ORP or ORP measurement.

I'd clean the ORP probe, and also continue to use some sort of GFO to deal with the phosphate.

That is 1.8 ppm phosphate?

 

[Buganddoug]

1.8 is right. That is what It tested with my Hanna meter. I tested it today and I got .52. I just put a new ORP Probe on last week thinking. It might be going bad.
I do not use Ozone. My RO Water TDS out put is 0. When I make up my water and IO salt for a water change my phosphate is 0.

 

[Buganddoug]

I did test the Kent carbon for phosphates and I get 1.0 with the Hanna meter.
My LFS took the Kent carbon back and gave me Black Magic Carbon which. I do like and use.

 

[Buganddoug]

Jon Warner had me put 1 pack of the IO Gel food in 5 gallons of RO Water and a pump then run the pump for one hour and test for phosphate. I did that and I got 3.5 on my Hanna meter. I did that test three times and came up with 3.5 each time. My ro water. Tested 0 at the start if the test.

 

[Bugger]

How long was running in your system. I also used it and my po4 is looking kind of high how much did you use

 

[Randy Holmes-Farley]

Jon Warner had me put 1 pack of the IO Gel food in 5 gallons of RO Water and a pump then run the pump for one hour and test for phosphate. I did that and I got 3.5 on my Hanna meter. I did that test three times and came up with 3.5 each time. My ro water. Tested 0 at the start if the test.

Those sorts of phosphate tests are largely meaningless. 99% of the phosphate in foods doesn't come out by soaking in water because it is part of the tissue: phospholipids, DNA, proteins, etc.

All foods are loaded with TONS of phosphate. There is no way around that

 

[Buganddoug]

I got 1.9 pound container Of Kent and I ran it for1 month. I was changing it Out once a week at two cups each time. That might part of my phosphate problem.

 

[Randy Holmes-Farley]

I have no reason to think Kent carbon has a phosphate problem. I think the problem is something more toxic.

 

[Bugger]

Have you been using any calcium cloride? But the test kits still measure phosphate in the water. the levels still effect the health of the tank. No?

 

[Randy Holmes-Farley]

Yes, phosphate needs to be brought down if it is that high.

 

[Buganddoug]

I have no reason to think Kent carbon has a phosphate problem. I think the problem is something more toxic.

I agree but when I take a half a teaspoon of Kent carbon in 1 cup of RO water that test 0 on Phosphate before the carbon was put in. Then I stir it up and test it one hour later I get 1.00 on my Hanna meter.
I just did this test on the Black Magic Carbon and I get 0.00 on my Hanna meter.

 

[Buganddoug]

Have you been using any calcium cloride? But the test kits still measure phosphate in the water. the levels still effect the health of the tank. No?

No I do not use calcium cloride.

 

[Buganddoug]

I just put in a Poly Pad.

 

[Randy Holmes-Farley]

I agree but when I take a half a teaspoon of Kent carbon in 1 cup of RO water that test 0 on Phosphate before the carbon was put in. Then I stir it up and test it one hour later I get 1.00 on my Hanna meter.
I just did this test on the Black Magic Carbon and I get 0.00 on my Hanna meter.

Right. But what gets lost in most peoples use of this test is the dilution factor.

When you put the normal amount of carbon in an aquarium (say, 1 cup per 100 gallons of water), that number is way, way lower. Much less than you add every day in foods.

 

[Buganddoug]

Right. But what gets lost in most peoples use of this test is the dilution factor.

When you put the normal amount of carbon in an aquarium (say, 1 cup per 100 gallons of water), that number is way, way lower. Much less than you add every day in foods.

I under stand.

But what is causing my high ORP? There must be something I am missing. Could it be the GFO I am using? Or maybe When I used Kent carbon?
When I did a 40 Gallon water change yesterday my ORP drop to 360 and this morning it was up to 500.

 

[bertoni]

I suspect that 500 mV is a measurement error of some sort. Is the probe exposed to light? How was it calibrated?

 

[Buganddoug]

I suspect that 500 mV is a measurement error of some sort. Is the probe exposed to light? How was it calibrated?

No light at all. I calibrated with my RKE using 400mv ORP/REDOX calibration fluid. I give it about 15min before I save calibration in my RKE.

 

[bertoni]

I'm not sure what's happening, then. I might try measuring a cup of water well away from the tank, and maybe consider moving the reef controller away from the tank, too. We see a fair number of problems with electrical interference.

Personally, I would ignore the ORP value for the time being.

 

[Buganddoug]

I'm not sure what's happening, then. I might try measuring a cup of water well away from the tank, and maybe consider moving the reef controller away from the tank, too. We see a fair number of problems with electrical interference.
.

I will give it a try in the next day or two.