Crazy Low ORP

[d2mini]

Without daily ozone use, my redox is down around 150-165 mV.
Yes, the probe is clean. As my probe gets dirty, the redox readings increase in value.
Could probably stand to be recalibrated but it has always been this way.

My tank is doing great, sps are colorful and growing well. Fish are good too.
Just curious how/why it's so low and if it's an issue I would need to worry about.

 

[MrDJeep123]

What is your pH? If pH is fine and stable, then it may need recalibrated. Assuming I understand ORP correctly. :tongue:

 

[Randy Holmes-Farley]

It might just be a recalibration issue, but refugia tend to lower ORP.

Do you have a refugium?

 

[d2mini]

Like i said, it may need to be recalibrated again, but this is no different than it has always been. Well it's always been low. This may be a tad lower than normal.
Currently, this is my temporary 4'x4' holding tub, so no fuge is connected. Still working on my rebuild.
Normally I do have a fuge when the tank is set up and it has been more around 200.
Ph dips down to around 7.7 at night and up to around 8-8.1 during the day with my CaRx running 24/7 and Kalk in the ATO.

 

[Randy Holmes-Farley]

I personally wouldn't spend time trying to figure out why the ORP is low if everything is thriving.

 

[d2mini]

haha, ok. Just wanted to make sure.

Also, ORP can give you an idea of what's going on nutrient-wise, right?
I have really low nitrate in there, barely detectable and po4 is around .03
Last time I saw it drop this low was my tank was going through that mini crash with all my sps losing their slime coats. Lots of junk in the water!

Maybe i do need to recalibrate! lol

 

[joekool]

So your not using ozone?

I keep mine between 425 and 450 and my water is crystal clear. Using ozotech for ozone.

These numbers might work differently for most but I find water to not be so clear as in dirty when down below 400.

Other fellow reefers use the same settings as mine and we have mixed reefs but with more SPS.

Also I think that your probe is fine. They are tricky to calibrate rite. I feel that your ORP is probably correct. How clear is your water?

Also you may have to dial your light intensity back when you raise up the ORP due to more par and light transmittance through the water

 

[Randy Holmes-Farley]

haha, ok. Just wanted to make sure.

Also, ORP can give you an idea of what's going on nutrient-wise, right?
I have really low nitrate in there, barely detectable and po4 is around .03
Last time I saw it drop this low was my tank was going through that mini crash with all my sps losing their slime coats. Lots of junk in the water!

Maybe i do need to recalibrate! lol

ORP doesn't respond to nitrate or phosphate. It does provide some indication of overall organic levels, but that's prety rough.

I discourage folks from thinking about low ORP as undesirable and higher ORP as desirable.

This has more:

ORP and the Reef Aquarium - Reefkeeping.com

 

[d2mini]

So your not using ozone?

I keep mine between 425 and 450 and my water is crystal clear. Using ozotech for ozone.

These numbers might work differently for most but I find water to not be so clear as in dirty when down below 400.

Other fellow reefers use the same settings as mine and we have mixed reefs but with more SPS.

Also I think that your probe is fine. They are tricky to calibrate rite. I feel that your ORP is probably correct. How clear is your water?

Also you may have to dial your light intensity back when you raise up the ORP due to more par and light transmittance through the water

I do use ozone normally, which would keep it in the mid to high 300's, but I haven't been using it the last couple months while everything is in holding.
Water seems clear enough but I only have a top down view.
https://www.reef2reef.com/forums/me...eeftastic-reef-part-deux-*-8.html#post2120985

 

[memori shots]

Hi guys I'm sorry to enter the thread late but can I use ozotech on my Eshopps proteins s300

 

[Randy Holmes-Farley]

I'm not a fan of regularly using ozone in a skimmer because the flow is too high to treat the effluent with carbon to remove the toxic oxidants.

 

[hart24601]

I'm not a fan of regularly using ozone in a skimmer because the flow is too high to treat the effluent with carbon to remove the toxic oxidants.

How about even very small amounts of ozone, 5mg/hr and under?

 

[reefcubed]

Randy I read your article ORP and he Reef Aquarium (the majority of it that I could follow). I bought an ORP probe because of paranoia. When watching my fish I always feared as though they were breathing heavy. I have a full sps tank with refugium, skinner, carbon and gfo reactors, etc. ORP probe was the only thing I could think of to help test my fears. ORP appears to be stable between 200-300. I do feed a lot and i do have a heavily stocked tank. But it is sps dominant, is ORP too sensitive to determine if oxygen is too low for fish? I have my cabinet pretty air tight so I could see it not getting much gas exchange down there, but I have a rimless cube with no canopy. 3 mp10's pretty much running full bore in my 93 gallon cube. Weather has been nicer so I have tried to keep windows open as much as possible, but that can't be s permanent fix. I guess I'm curious if anything stands out to you or if I'm just being hypersensitive. Also, per your article, so Vitamin C is a reducer? I was dosing it to help treat lymphocystis on one of my tangs, I never considered it to be a significant additive to reducers. Thank you so much in advance for your response

 

[Randy Holmes-Farley]

How about even very small amounts of ozone, 5mg/hr and under?

I run a tiny bit of ozone into my skimmer for about 1 day every month or two to clear yellowing. Any more than that and I not would want the oxidants getting into the display.

 

[Randy Holmes-Farley]

Randy I read your article ORP and he Reef Aquarium (the majority of it that I could follow). I bought an ORP probe because of paranoia. When watching my fish I always feared as though they were breathing heavy. I have a full sps tank with refugium, skinner, carbon and gfo reactors, etc. ORP probe was the only thing I could think of to help test my fears. ORP appears to be stable between 200-300. I do feed a lot and i do have a heavily stocked tank. But it is sps dominant, is ORP too sensitive to determine if oxygen is too low for fish? I have my cabinet pretty air tight so I could see it not getting much gas exchange down there, but I have a rimless cube with no canopy. 3 mp10's pretty much running full bore in my 93 gallon cube. Weather has been nicer so I have tried to keep windows open as much as possible, but that can't be s permanent fix. I guess I'm curious if anything stands out to you or if I'm just being hypersensitive. Also, per your article, so Vitamin C is a reducer? I was dosing it to help treat lymphocystis on one of my tangs, I never considered it to be a significant additive to reducers. Thank you so much in advance for your response

I do not believe that ORP is useful for tracking O2 levels. Low ORP does not necessarily imply low O2 in a reef tank.