Mv reading on 1week old set up ?

[Mattcraughwell]

Hi,

Looking for some advice as to what levels of mv reading on a newly set up reef tank to expect as ?

My main display is 600lts, sump 100ltrs & water change/extra water volume tank 160 ltrs Now i added some ozone yesterday for about 2 hrs and the reading did start to climb to 90mv but as soon as i switched it off with in 2 hrs it was back to the starting mv of 50mv



I have 90kg cured live rock in main display with 3 tunzes providing 30'000 lts flow, i plan to have an sps tank and for this i want to run ozone via mv controller through my deltec apf850, t mv reading this morning was 40mv.



Now i think this is low but cant find any referance to what reading i should expext as my tanks so young. i havent got any test fluid but will try to get some tomorrow but thing the probe is working to some degree as when i place it in a sample of drinking water the reading shoots up to well over 250mv

[Jens Kallmeyer]

HI

Switch off the controller, put it into the cabinet and forget about it for another month or so. Your tank is cycling and no matter how well you rock is cured, there will be some decay. Give it some time and relax, running Ozone is absolutely pointless at this time. Oxidizing everything away will not be beneficial when you try to establish biological cycles.
Another point, I would NEVER EVER (!) use an ORP controller to switch Ozone on and off. The hobby ORP electrodes are too finicky to be a reliable way of controlling ozone. There are some very good ORP electrodes on the market but I doubt you are willing to pay that price. If your electrode fails and reads too low your tank may easily be wiped out by and Ozone overdose.
My very personal recommendation is to ditch the ORP electrode, plug in the Ozonizer directly to the skimmer and usea VERY small setting. Let it run for a day and make sure that the outflow of the skimmer goes through some activated carbon to capture all free ozone before it enters the tank. If you have the desired effect and no side effect, then you are all set, otherwise increase the dose very carefully.
That's just my 0.02$

You say that your electrode is apparently working because it shoots to 250 mV in clean drinking water. If your tank water would increase in ORP from 50 or 90 mV to 250 mV, what would this tell you?

Best wishes

Jens

[Mattcraughwell]

Thanks jens,

Now in cupboard and think it'll stay there for a few months.


Matt

[bertoni]

http://reefkeeping.com/issues/2006-03/rhf/index.php
http://reefkeeping.com/issues/2006-04/rhf/index.php

Those two article discuss ozone. I would always use a controller, if I was running ORP, as a safety measure. I also don't see any reason why running it while curing live rock is a bad idea. In the end, I chose not to run ozone at all for various reasons, but I wouldn't run it without an ORP controller.