How to use ozone when ORP is >400

[carsonc]

I have my orp controller set so that the ozone shuts off at 350. For the past few weeks my ORP is staying around 400 so The ozone gen never comes on. The water looks good and all the tests are normal for this tank, but you can tell that there is no ozone being used. The water does not have that invisible look that it had when the ozone was running.
The skimmer is also not working quite as well as before.
I have read that an UV does some of the same things that ozone does. Has anyone been down this road before. Would a UV be a good thing to add.
The only problem with the tank is some green agae that wants to grow on the sand, but it was doing this while the ozone was still be used.
Carson :?:

 

[clayswim]

UV works entirely different from ozone. While ozone works by oxidizing any organic compound it comes into contact with, UV penetrates the DNA structure of living organisms and disables (or inactivates) their ability to reproduce. When the light is strong enough and the flow is low enough UV can kill most organisms passing by it. Ozone will not only kill most organisms, but it also oxidizes their dead tissue after doing so. This isn't necessarily a great thing by the way, since the waste produced in the oxidizing process in still in the water. UV also has no impact on skimmers.

The algae that live in the tank won't be affected in the least by either one of these. They can only react to whatever is brought to them. Both can destroy free-floating algae in the water, the so-called "green water"; but unless the ozone or UV rays are released into the tank water itself they'll have no impact on your sand algae. Releasing them into your tank water is a bad idea by the way

Clayton

 

[carsonc]

Thanks for the reply clayswim
I did not think that they would affect the alge, I have that because I overfeed and the circulation could be increased some.
I was wondering that since the ozone is no longer being used would the UV be a worth while addition to the tank.
Would it make the water look as clear as the ozone did.
Thanks Carson

 

[clayswim]

No, a UV sterilizer wouldn't clear your tank up like ozone did; although it sometimes helps a bit. Do you use activated carbon? Using carbon at least a week out of the month can clear up any discoloration in the water. For that reason and to remove any possible chemical attacks by corals I use it 24/7 in my tanks.

Clayton

 

[DonW]

Thanks for the reply clayswim
I did not think that they would affect the alge, I have that because I overfeed and the circulation could be increased some.
I was wondering that since the ozone is no longer being used would the UV be a worth while addition to the tank.
Would it make the water look as clear as the ozone did.
Thanks Carson

Its not going to clear your water like ozone does. But UV will improve your water quality, ozone or not. Its not really about one thing in particular to improve water quality. Its all the small things like ozone, uv, rowa and carbon that all add up to good water quality.
I'd probably clean and recalibrate your orp probe, since your orp is more likely to be much lower than its reading.

Don

 

[mojoreef]

You have to look at UV as more of a dissinfector, dealling more with removing living organic critters. The UV light itself however will create a small amount of ozone on the glass shield, that maybe what you were refering to. Algae I guess would be impacted kinda indriectly by the use of ozone as it is taking out organics that would be used by the algae as a nutrient source.
As Clayton mentioned it wont have to much of an effect on algae on a sand bed. Most of this algae is being feed by nutrients upwelling from the bed itself so the ozone will never have a chance to see it or oxidize it.


Mike

 

[dnjan]

Agree with DonW concerning checking the calibration of your ORP probe.

Also, you could gradually "dial-up" your controller so that you add ozone at higher ORP readings. Watch you animals calefully for signs of stressing, and give at least a week between changes in settings.

 

[Carloskoi]

ORP probes should be cleaned and calibrated at least weekly as the reading will drift upwards from the organics in the water.

i have found that my hot tub is a good way to clean the probe. i just put it in the hot tub for a few hours and the chlorine does the trick. you can also use household bleach. i'm not sure how dilute to use it but a few oz in a gallon of water will probably do it.

there are two different types of ozone generators. one type uses a corona discharge and the other uses a UV lamp. i believe it is a different freqency and is of a higher wattage than the one just to kill algae.

ozone is an indescriminant killer, oxidizing everything it comes into contact with.

Carl

 

[Boomer]

Ozone will not only kill most organisms, but it also oxidizes their dead tissue after doing so.

ozone is an indescriminant killer, oxidizing everything it comes into contact with.

Not in a reef tank, as the O3 is not high enough. O3 in a reef tank lasts about 2 sec in that skimmer before it is not O3 anymore. If there was any killing it is because you are not post treating with GAC and are letting the hypobromite ion concentration increase

Carlson

I will bet anything it is your probe, that has algae growing on it, which rasies the ORP. Clean it with vinegar or with a probe cleaning solution or a pH buffer 4 and that 400 mV will drop to the 300's mV

 

[clayswim]

Boomer, what I was getting at is that O3 oxidizes whatever it contacts. Even it if it's for two seconds thats still true isn't it?

Clayton

 

[Boomer]

Yes, if the concentration is high enough. In almost all skimmers there will be oxidation with ozone, no question about, as the concentration is high enough that but the concentration is not high enough to really kill much of anything. That hypobromite ion that is created is also oxidizing things it comes in contact with.

 

[carsonc]

Thanks all for the info
I have a bottle of orp check fluid coming next week, as I did not trust the probe. The probe is only 1 month old as the old one had failed. I cleaned the new probe before putting it into the tank and have cleaned it again about a week ago. After the cleaning it would read lower but then within a day it was back over 400.
I thought 400 (if accurate) is about as high as the orp should go so I had the monitor set at 350
When I use carbon I put it in a net bag and place it in the water flow, after just a few days the bag that it is in is covered with stuff that I would rather have circulating so the skimmer could remove it, so I do not use carbon very often.
The water in the tank has no color but when the ozone was running it looked different, hard to describe, just more clear
It sounds like there is no real down side to a UV I will probably add one, In a 75 gal tank (100 gal total with sump) would a 25 watt UV be large enough.
As to the sand bed releasing alge-grow, that's a another can of worms by itself.
Carson

 

[DonW]

Thanks all for the info
I have a bottle of orp check fluid coming next week, as I did not trust the probe. The probe is only 1 month old as the old one had failed. I cleaned the new probe before putting it into the tank and have cleaned it again about a week ago. After the cleaning it would read lower but then within a day it was back over 400.
I thought 400 (if accurate) is about as high as the orp should go so I had the monitor set at 350
When I use carbon I put it in a net bag and place it in the water flow, after just a few days the bag that it is in is covered with stuff that I would rather have circulating so the skimmer could remove it, so I do not use carbon very often.
The water in the tank has no color but when the ozone was running it looked different, hard to describe, just more clear
It sounds like there is no real down side to a UV I will probably add one, In a 75 gal tank (100 gal total with sump) would a 25 watt UV be large enough.
As to the sand bed releasing alge-grow, that's a another can of worms by itself.
Carson

The skimmer is "supposed" to flow through the carbon. If the outside of your carbon bag is collecting detritus in a few days, its in to low of flow area.

Don

 

[clayswim]

25-watts is more than enough on that size tank; you could get by with a 15-watt easily. The important thing to remember with a UV sterilizer is low flow. The slower the water moves through the UV the more contact it receives from the light. For example, on most 25-watt units you can kill algae up to about 1,200GPH, but under 400GPH is needed for some organisms. Aqua Ultraviolet has a good sizing page here... http://www.aquaultraviolet.com/sizing.html

Clayton

 

[Carloskoi]

i have a 40 watt on my 1000 gallon Koi pond and on my 20,000 gallon koi pond i have a 175 watt unit. my water stays clear.

the 40 watt gets about 2000 gph and the 175 watt unit flows 7500 gph. the absolute minimum for the 175 watt unit is 3000 gph.

Carl

 

[carsonc]

Thanks again all for posting
I will probably go with the 25 watt maybe the 15 (depends on the size diff) . Some of them (the Aqua I think) have a internal cleaning thing, this sounds like a good idea, any body know of a down side to the this.

Don You are probably correct about the low flow thru the bag of carbon, I do not have much flow thru the sump area about 250 gph is all, I have all the larger pumps on closed loops. I made a basket to fit the outflow of the skimmer (Aqua Medic t 1000) that holds the carbon bag. The flow thru the skimmer is gravity fed from one of two returns from the overflow box, so the flow thru the skimmer is about 100 gph and that is what is going thru the carbon.

Aquatic eco Sys has sent the orp fluid and I should get it next wed.
Thanks again
Carson

 

[carsonc]

Well I got the test solution for the orp meter and it is 470 mv solution, my meter says it is 590. I talked to Milwaukee inst. and they said it is probably a bad probe and not the calibration of the meter.
I will get a new one and test again
Carson