Disolved Oxygen in our Reeftanks - Who else measures it ???

[PSXerholic]

Disolved Oxygen in our reef tanks! Who else measures it???

Since Reef systems nowadays become more compact, artificially loaded with bacteria to accelerate and manage nutrient export, it can happen very quick that something goes wrong.

In my personal case I was always wondering when issues in the tank appear, corals do not look as healthy as they can be, if it has to do with insufficient oxygen levels in the tank.
For example when battling after my restart of the tank a few months ago some bubble algae coming out of the rocks, I usually reduce the Air inlet on the skimmer and run much finer bubbles and bubble algae disappears usually within a few weeks.
After a few days I feel that the water becomes a bit more haze and SPS do not look as happy as usual.
To be quite honest, I designed my 300G system very compact, and only use a 40G Breeder that contains now a Rollerfilter, a large skimmer and the return pump! No huge sump with tons of baffles etc.
Long story short, if the Skimmer is operating with the air valve fully open, the water is almost crisp and clean and I thought I will investigate this with the use of an Oxygen meter.

I would appreciate if anyone else has some results to share from their tanks, knowing not many people would have an DO monitoring device.

Also this device allows me to compare the oxygen levels in the house and within the enclosed stand.
Right now the above reading of 7.7mg/L is done with pretty clear water, skimmer air valve fully open, and happy corals.

-Andre

 

[Ranjib]

i am also curious, tagging along

 

[PSXerholic]

i am also curious, tagging along

Yep, hope to get some numbers from other Reefer’s!!!

 

[norfolkgarden]

Was just surfing. Is this a good meter. Seems to be a good price for it.

 

[PSXerholic]

Was just surfing. Is this a good meter. Seems to be a good price for it.

The one I use I was recommended to buy, since it had temp and salt compensation.
Also it can be used for DO in Air, so you can map outside, compare the house and measure inside canopies and stands.

 

[PSXerholic]

I measured yesterday midday the sump section.
Was wondering, tank was 7.7/7.8, sump entry was 7.6/7.7 and the skimmer section and return was measurable lower with 7.3/7.4 ............

Tank dropped in the night to 7.4 this morning.
Skimmer air inlet fully open, stand open.

It appears that larger bubbles in the skimmer bring down DO levels.................
@Diesel

 

[PSXerholic]

Seems to be another box of Pandora, ugh.
It sort of changes my mindset about skimmer, nanobubbles and Gas exchange in a skimmer.

Would like to understand now more about the oxygen exchange in a skimmer body by the bubble sizes created inside. Seems that there is a good Co2 exchange into the water, however less efficient oxygen exchange via the bubbles in the skimmer. Also the way the skimmer bubbles are created such as smashed and crushed by a needle impeller, makes a big difference to like the traditional air stone bubbles in skimmer in the ol days.

So in a nutshell, do the bubbles in the skimmer really release sufficient oxygen into the water column?
Would a large tank surface with certain movement and surface velocity may be allow a better oxygenation, with less Co2 induction?????
Would it mean, that if keep my Skimmer off daily for hours, it would be better for the oxygen in the tank since less Co2 is dragged in? And just use the skimmer for biowaste export only instead of the current picture I have that the Skimmer is bringing in fresh oxygen in? Right now it looks like the skimmer supports oxygen export

@Cruz_Arias for help.
Is Nano bubbling bringing in oxygen, aside from biowaste export???

-Andre

 

[MARK M. DAVIS]

Dissolved Oxygen is a real thing. Skimmer, water flow/circulation, surface agitation. Fish get sluggish. Corals will not PE.

 

[MARK M. DAVIS]

Weirs and waterfalls will break up water surface tension, too.

 

[MARK M. DAVIS]

Many times the lack of oxygen is caused by things like bacteria using up the oxygen. Blooms will deplete oxygen, fast. Eliminate the contributors and you shouldn't have a dissolved O2 issue. You still need to maintain good skimming to remove excess bacteria and nutrients with proper water surface gas exchange.

 

[Subsea]

Larger diameter bubbles move more water. The larger air bubbles themselves transfer less oxygen than smaller bubbles. In previous studies at intensive fish aquaculture using air bubbles, the vast majority of the gas exchange happens at the water surface.

Skimmers bring in room air which is often oxygen low and co2 high. In some cases this caused low pH in reef tanks.

I prefer redox measurement for long range stability. Lack of oxygen will kill fish faster than any other one thing. When I used oxygen monitoring, it was tied into alarm that sent a text.

 

[Reefahholic]

I'm very interested to see just how much O2 will drop with LaCI dosing. The PH definitely drops a bit.

 

[PSXerholic]

Larger diameter bubbles move more water. The larger air bubbles themselves transfer less oxygen than smaller bubbles. In previous studies at intensive fish aquaculture using air bubbles, the vast majority of the gas exchange happens at the water surface.

Skimmers bring in room air which is often oxygen low and co2 high. In some cases this caused low pH in reef tanks.

I prefer redox measurement for long range stability. Lack of oxygen will kill fish faster than any other one thing. When I used oxygen monitoring, it was tied into alarm that sent a text.

Great info, I personally know already some of that but many other's don't, so guys keep the infos coming.

Interesting note about the bubble size in the skimmer.
Focused on the bubble size and results of different oxygenation by these, I'm tending now to perform 2 variations of testing just for the next step and see how the tank will trend concerning DO.
a.) Run much finer air bubbles (reduced air inlet) in my Twin turbo skimmer (2 pumps) - Co2 scrubbed
b.) Run the skimmer only for limited time during the day from 11am - 5pm - Co2 scrubbed. Air Inlet then fully open and with reduced air.

Also like to introduce MNB from a Activated Carbon / Co2 scrubbed air reactor.....
but that's for later.

 

[PSXerholic]

I also measured the DO on the Nitrate reactor outlet with 6.8 yesterday. Sure it's lower since the bacteria in the reactor consume oxygen for denitrification.
Wondering if DO along with Delta No3 (In vs. Out) can provide a better understanding of the Nitrate reactor performance..........

 

[Reefahholic]

I also measured the DO on the Nitrate reactor outlet with 6.8 yesterday. Sure it's lower since the bacteria in the reactor consume oxygen for denitrification.
Wondering if DO along with Delta No3 (In vs. Out) can provide a better understanding of the Nitrate reactor performance..........

Sounds logical to me. What was the DO going in? Is the NO3 coming out a lot lower? Or just minimal?

 

[Diesel]

I measured yesterday midday the sump section.
Was wondering, tank was 7.7/7.8, sump entry was 7.6/7.7 and the skimmer section and return was measurable lower with 7.3/7.4 ............

Tank dropped in the night to 7.4 this morning.
Skimmer air inlet fully open, stand open.

It appears that larger bubbles in the skimmer bring down DO levels.................
@Diesel

Why you have large bubbles in your skimmer?
They suppose to look like a milky swirl in the reactor.

 

[Diesel]

Seems to be another box of Pandora, ugh.
It sort of changes my mindset about skimmer, nanobubbles and Gas exchange in a skimmer.

Would like to understand now more about the oxygen exchange in a skimmer body by the bubble sizes created inside. Seems that there is a good Co2 exchange into the water, however less efficient oxygen exchange via the bubbles in the skimmer. Also the way the skimmer bubbles are created such as smashed and crushed by a needle impeller, makes a big difference to like the traditional air stone bubbles in skimmer in the ol days.

So in a nutshell, do the bubbles in the skimmer really release sufficient oxygen into the water column?
Would a large tank surface with certain movement and surface velocity may be allow a better oxygenation, with less Co2 induction?????
Would it mean, that if keep my Skimmer off daily for hours, it would be better for the oxygen in the tank since less Co2 is dragged in? And just use the skimmer for biowaste export only instead of the current picture I have that the Skimmer is bringing in fresh oxygen in? Right now it looks like the skimmer supports oxygen export

@Cruz_Arias for help.
Is Nano bubbling bringing in oxygen, aside from biowaste export???

-Andre

The name says it all, dissolved oxygen.
O2 or Ho2 both have Oxygen.
Here a link what it it does,
https://www.fondriest.com/environmental-measurements/parameters/water-quality/dissolved-oxygen/

 

[vetteguy53081]

The amount of oxygen water can hold (saturation) is dependent upon water temperature, salinity and atmospheric pressure. As water temperature increases, the amount of oxygen the water can hold decreases. Likewise, as salinity increases, less oxygen can be dissolved into the water. At greater pressures, water can hold more oxygen. For example, more oxygen can be held in water (of equal temperature and salinity) in Miami than at the much higher altitudes of Denver.

DO may be supplemented by use of an aeration system. In an aquarium, this aeration system often consists of only a simple air pump, air tubing and airstone. While this type of system does not greatly increase the oxygen level by pumping air and in turn oxygen into the tank, it can help circulate the water and break the surface tension of the water to increase the rate of diffusion.

 

[Diesel]

The amount of oxygen water can hold (saturation) is dependent upon water temperature, salinity and atmospheric pressure. As water temperature increases, the amount of oxygen the water can hold decreases. Likewise, as salinity increases, less oxygen can be dissolved into the water. At greater pressures, water can hold more oxygen. For example, more oxygen can be held in water (of equal temperature and salinity) in Miami than at the much higher altitudes of Denver.

DO may be supplemented by use of an aeration system. In an aquarium, this aeration system often consists of only a simple air pump, air tubing and airstone. While this type of system does not greatly increase the oxygen level by pumping air and in turn oxygen into the tank, it can help circulate the water and break the surface tension of the water to increase the rate of diffusion.

At a normal level we keep our systems at a 7.8 osmotic pressure on DO is perfect.
You will measure different values in different locations in the tank and sump.
The question is what is a sweet spot or acceptable level.

 

[mcarroll]

Maybe someone else can double check me, but from a quick google scholar the numbers in this thresd seem to be pretty typical of reef numbers in the wild. Not bad or too low.

Doesn't seem likely DO in this thread is low enough to cause an issue...doesnt even seem to vary significantly.

Anyone else find similar or different conclusions?

Also the pic isnt clear...what meter is being used?