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

[PSXerholic]

People following my Built thread see I play with the new Skimmer configuration.

So I did a background experiment while I was waiting for my Lifereef Skimmer parts to arrive.

I did buy a cheap $10 1" Venturi nozzle from Amazon, that looks similar to the Mazzei Venturi I ordered.
So I did install that particular Venturi pipe on the Skimmer on Monday evening with terrible results !!!
PH kept dropping and Oxygen levels did drop as well, over the last few days terrible low.
Even while the Air withdraw was only a little bit higher than in the standard diffusor on the Skimmer, and the bubbles look evenly finer than with the cheap venturi, the results were very different.
Yesterday evening I did put on the standard venturi, and PH in the night increased compared to the day before !!!

Now looking forward to the official Mazzei Venturi pipe ;-)
I should have everything in the mail tomorrow, so it's going to be installed tomorrow night.

 

[Randy Holmes-Farley]

If the orp is increasing even if prob is off , I would think that the water is cleaner with the new skimmer increasing orp.
I might need to get a meter and see. I know if I run the bubbles in my skimmer smaller orp increases / if I run large bubbles orp decreases.
I run all gf-signet probes that are calibrated way different than hobby grade probes.

Bear in mind that ORP is strongly dependent on pH, and skimming and aeration in general will impact pH and hence ORP, independent of O2 or organics.

 

[Dr. Dendrostein]

I haven't read all comments, sorry if this has been mentioned. Have you try if possible, install air pump outside home for skimmer.
Larger refugium, also I use Hiatt filtration system, alot smaller foot print for filtration and acts like a refugium.
I monitor ORP, because my controller has it.
I heavy feed, use tap water, no skimmer. And yet ORP up to 350. Pump outside. Hope this helps

 

[Randy Holmes-Farley]

I haven't read all comments, sorry if this has been mentioned. Have you try if possible, install air pump outside home for skimmer.
Larger refugium, also I use Hiatt filtration system, alot smaller foot print for filtration and acts like a refugium.
I monitor ORP, because my controller has it.
I heavy feed, use tap water, no skimmer. And yet ORP up to 350. Pump outside. Hope this helps

If we are talking about O2 levels, that won't matter appreciably. Even in a home with highly elevated Co2, the O2 level is not lowered much since it starts out with so much more.

 

[Dr. Dendrostein]

Right, if disolve O2 levels are reached in aquaria. Doesnt matter, trying to add more. I see says the wise man

 

[PSXerholic]

If we are talking about O2 levels, that won't matter appreciably. Even in a home with highly elevated Co2, the O2 level is not lowered much since it starts out with so much more.

Correct Randy. And that I have looked at in my measurements and it's proven again.
@Jomama
I measure the Oxygen inside vs. outside occasional with the results that both o2 levels are basically the same. Only difference is that outside air has much less Co2, hence the effect on the tank is by using outside air is that the PH is higher using outside air, hence I use a Co2 scrubber on the skimmer while using inside air.

The O2 levels in the water are affected by the bubble size, reaction or dwelling time, surprisingly a lot by the type of injector (influencing the bubble size) and of course the amount of air withdrawn by the skimmer where the more the better does not apply!

Got my skimmer extension and still waiting for my Mazzei Venturi on the Lifereef skimmer.
Yesterday I measured 8.8mg/L DO earlier in the day means the oxygenation and greater O2 levels are longer present during the day now. I expect the theoretical peak was maybe a bit higher but I wasn't home all day to measure it. I think this particular value or range is as high as it can get, the water turned out very very clear and crisp compared to the days before. Polyp Extension is also better apparently.

I do believe however, using outside air is a better choice to feed the skimmer since there are many more other gases, chemicals and substances in the house air from furniture, cooking, simply living in the house that would be undesired to be injected into the tank. So outside air is useful for sure for better health of the reef! In my case I'm always concerned about the Mosquito sprayer few time a week :-(


That's the current setup! Right now it draws about 7 L/hour of air, according to the flow meter.

 

[CNDReef]

That’s a beast of a skimmer man

 

[PSXerholic]

That’s a beast of a skimmer man

Yeah, really is ;-)
The large SKIMZ Monzter could not handle the tank anymore after only 11 months of growth
Nice problem to have. I guess the oxygenation was a big issue, glad I found it!!!

 

[CNDReef]

I bought a svs30 that’s way oversized for a 40 breeder and a 20 sump and the more I read about your experience the more I realize I made the best choice.

 

[PSXerholic]

I bought a svs30 that’s way oversized for a 40 breeder and a 20 sump and the more I read about your experience the more I realize I made the best choice.

Good choice for sure.

The stupid reason I went with a compact SKIMZ needlewheel skimmer was, that I was too stubborn to accept that I may need a large skimmer for the build. I wanted to keep everything in the stand and my previous Lifereef was too tall and needed a bigger one. I ran the previous Lifereef skimmer successful on a 220, but prior the flood the skimmer became too small for the bioload and instead of an extension I went with the SKIMZ model.

Always loved the Lifereef skimmers. In your case run it more dry with a lower water level to avoid over stripping the water. Like 1,5-2" below the neck to allow stiff and dry foam. Once a day 1ml of Selcon classic helps to make the skimmer not working effectively and you sort of can run the skimmer continuously for aeration, instead of turning it off for a few hours, hint hint !!!

For future with the beauty of a variable pump, I will later connect the APEX to reduce the flow in the night which will help to keep more food and waste in the tank for the corals during the night.

 

[PSXerholic]

Simply said, the investment of $300 in a DO meter was the best choice ever !!! Should have done that years ago!

 

[PSXerholic]

Correct Randy. And that I have looked at in my measurements and it's proven again.
@Jomama
I measure the Oxygen inside vs. outside occasional with the results that both o2 levels are basically the same. Only difference is that outside air has much less Co2, hence the effect on the tank is by using outside air is that the PH is higher using outside air, hence I use a Co2 scrubber on the skimmer while using inside air.

The O2 levels in the water are affected by the bubble size, reaction or dwelling time, surprisingly a lot by the type of injector (influencing the bubble size) and of course the amount of air withdrawn by the skimmer where the more the better does not apply!

Got my skimmer extension and still waiting for my Mazzei Venturi on the Lifereef skimmer.
Yesterday I measured 8.8mg/L DO earlier in the day means the oxygenation and greater O2 levels are longer present during the day now. I expect the theoretical peak was maybe a bit higher but I wasn't home all day to measure it. I think this particular value or range is as high as it can get, the water turned out very very clear and crisp compared to the days before. Polyp Extension is also better apparently.

I do believe however, using outside air is a better choice to feed the skimmer since there are many more other gases, chemicals and substances in the house air from furniture, cooking, simply living in the house that would be undesired to be injected into the tank. So outside air is useful for sure for better health of the reef! In my case I'm always concerned about the Mosquito sprayer few time a week :-(


That's the current setup! Right now it draws about 7 L/hour of air, according to the flow meter.

Got a PM from a reader that noticed the little detail fact, that the skimmer is drawing now about 1 liter more air than before!!! Great catch Sir.
I contribute this to the fact that the skimmer is about 12-14" lower than before which provides less backpressure to the pump, hence more flow and more air withdrawn by the venturi.
I expected more water flow, that was the reason for lowering the skimmer to the floor.

 

[Gibo]

it will be interesting trying dosing a bit of ozone in the skimmer to see what happen on DO..

 

[PSXerholic]

it will be interesting trying dosing a bit of ozone in the skimmer to see what happen on DO..

Actually did this just in the last few days! DO increase a bit while using Ozone, as expected. I just using a bit Ozone now.
Seems that DO is not the only issue I have.
See next post, lol.

 

[PSXerholic]

After a while now and an up and down on new issues, I'm back to the problem of low PH, even while DO is relatively high!

I did play around a lot with the skimmer, Co2 scrubbing etc. and came to the conclusion that it may not be the reduction of the Co2 on the inlet side of the overall system.

The issue seems to be accumulation of Co2 and insufficient degassing.
In the attempt over the last months to silence the tank system, less overflows, less waterfalls, less splashing noises etc. all contribute in theory to less degassing ability.

So it may be that there is simply an issue of Co2 accumulation in the tank by insufficient degassing .........

To support this theory, I installed a temporary conceptual trickle filter where the water from the overflows has to trickle through a few layers of eggcrate with a mesh, horizontally arranged.
Post a picture later. So the water is basically trickling through the layers open on the sides to allow co2 to degass.

Last days PH in the morning dropped down to 7.6...... :-(
So just installed this setup yesterday evening and PH this morning was up to 7.8, so it did show effect. Will see how this works out over a few days now.

 

[Belgian Anthias]

[QUOTE="Subsea, post: 5146655, member: 103573"

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.[/QUOTE]

A skimmer or an airstone makes a big difference I would think. The raising bubbles will not add much to the water column. I think it is the water to air echange at the surface wich makes the difference. A skimmer has very limited water - air exchanges.

Can ORP be used to determine the oxygen content? Is it possible to determine or estimate the oxygen content using ORP? How ORP monitoring will tell me there is not enough oxygen before it is to late? As the oxygen content may kill fish and other organisms faster as anything else how ORP reading may prevent this to happen?
As correct DO reading is a lot of work or and expensive, using ORP reading to determine DO would be an accessible solution, if it is possible. As far as I know it isn't!

 

[norfolkgarden]

Getting an Algae scrubber for the dual purpose of reducing nitrate in a more 'tank friendly' manner and hoping to increase Ph by 'eating' the CO2 on a reverse light cycle.

Will post after it's installed.

 

[Subsea]

[QUOTE="Subsea, post: 5146655, member: 103573"

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.

A skimmer or an airstone makes a big difference I would think. The raising bubbles will not add much to the water column. I think it is the water to air echange at the surface wich makes the difference. A skimmer has very limited water - air exchanges.

Can ORP be used to determine the oxygen content? Is it possible to determine or estimate the oxygen content using ORP? How ORP monitoring will tell me there is not enough oxygen before it is to late? As the oxygen content may kill fish and other organisms faster as anything else how ORP reading may prevent this to happen?
As correct DO reading is a lot of work or and expensive, using ORP reading to determine DO would be an accessible solution, if it is possible. As far as I know it isn't![/QUOTE]

In the mid eighties, when I first used DO monitoring equipment in marine environment, then the “in water” membrane probe was expensive and short lived. During that same time, I begin using ozone that feed into protein skimmer that went thru activated carbon.

After reviewing what the Germans are doing with hydrogen peroxide and after maximizing all gas exchange processes with emphasis on wet dry over coral rubble in all of my systems, I see a DO meter as an indispensable piece of equipment for AquacultureRanch operations.

 

[Belgian Anthias]

Using bio-reactors or -filters for removing and managing ammonium-nitrogen, DO is very important as the processes use a lot of oxygen. In a reactor the DO may go down fast at low flow rates. Some use ORP for monitoring or controling bio-reactors but ORP reading reacts to slow on changes in free oxygen to be useful and will not warn in time for to low DO.
When using ORP for monitoring the aquarium, ORP reading will not tell much about the free oxygen content on the moment of reading. ORP reading may give the user a fals feeling of security. For knowing the DO content one has to use a DO meter.
DO monitoring with an acurate oxygen meter is still expensive. That is why I prefer the use a bio-filter in a refuge instead of a -reactor for managing the ammonium-nitrogen content in a reef home aquarium. This way to low DO can easily be prevented by aeration and pH and alkalinity of the aquarium will not be influenced much by autotrophic processes.
Algae using ammonium-nitrogen to grow will consume alkalinity, algae using nitrate-nitrogen for growth will add alkalinity but will have a reduced growth rate. An algae scrubber may add oxygen and prevent CO2 build at night, a very good reason to use a refuge with algae, but the effect on pH and alkalinity depends on the nitrogen source used. Feeding an algae scrubber with the effluent of a nitrifying bio-filter will increase alkalinity.

 

[Malcontent]