Oxygen and how to increase it in an aquarium

[Sinatra]

G'day

Most of us have tried to increase the oxygen concentration in our cat tanks. This is often done via powerheads.

But I was wondering if people use other methods?

One method is to possibly use ozone. (?) I now it is used in saltwater aquaria.

Does anyone use it in freshwater?
Does it work?
What were the results when you used it?
What equipment did you use and how was it all hooked up?

Does anyone use something else? (Other than air bubbles/water falls/powerheads)

Thanks very much Sinatra

[syno321]

A friend of mine came over to my place a few years ago with an oxygen meter and sampled all of my tanks. The best reading was from a system that had a 4 foot degassing tower. If you don't want to go that route the next best reading, and comparitively high, was in tanks where I had a spray bar from a canister filter positioned at the water surface pointing horizontally along the surface at one end of the tank.

[UNTgolf]

Temperature, pressure,Surface area, speed of water, and depth all affect the quantity of oxygen that will be dissolved in the body of water. In addition to that salinity will affect the dissolved oxygen capacity of water. Surface aggitiation(formentioned, which I think is any easy way of increasing o2.Biochemical oxygen demand also effects oxygen, but Temp is a big factor and will set a limit on how much dissolved oxygen almost inregardless of most other factors if they are extreme.Nutrient levels of potassium, nitrogen and phosphorus affect plant growth. Excessive algae growth can generate massive die-offs which deplete the oxygen levels.
Personally I think the ozone generator would be a waste of money for you. I would buy a wide shallow tank with power heads and run from there!

[MatsP]

I'm not sure why one adds ozone to a marine tank - I've never kept marine fish. However, I don't think it's a clever thing to add to freshwater - ozone is a highly reactive element, and it would oxidise matter in the tank, and under certain circumstances, probably also create hydrogenperoxide - yes, the stuff Marilyn Monroe was dying her hair with!

If you really want to add more oxygen to the water, get the water moving along the surface of the tank. One of many ways to do that is a big (long) air-stone that sits along one of the sides of the tank... Or, spray-bars going along the surface of the water.

Anything but the surface doesn't really matter - yes, you can add air-bubbles below the surface, but those will have a minute effect unless the entire bottom of the tank is a big air-stone with a HUGE pump... I calculated some other time that the surface area of the tank is something like a million times larger than one air-bubble, so you need a million air-bubbles in the tank at any given time to have the same effect as the surface of the tank - which I doubt that it can be achieved without the tank looking like a newly shaken bottle of sprite...

--
Mats

[Sinatra]

Many thanks for the replys so far.

In a marine tank the Ozone serves two purposes. The first is to oxidise (kill) everything it comes into contact with.

The second thing it does is to increase the oxygen content of the tank.

PS. Ozone does not enter the tank as the water is passed through carbon. This prevents any harmful ozone from entering the tank.

I know a powerhead may be a good option but it cannot be the only method, because the fish I intend on breeding need a temp of 29 degrees C and it seems it is almost impossible to get the required oxygen content of upto 10ppm with powerheads.

What do you do with your tanks to increase their oxygen levels and induce some spawning action?

Thanks Sinatra

[MatsP]

If the fish normally lives in 29'C water, then I expect that they do not require 10ppm of oxygen to breed - just based on the fact that saturated oxygen at 25'C is 8.6ppm, and saturation at 29'C is somewhere between 6 and 7, I should think that this is a fair assumption... Unless these only breed when there's extreme highpressure, or live far below sea-level in fresh-water...

Here's a chart and some formulas that can be used to calculate the dissolved oxygen levels:
http://waterontheweb.org/under/waterquality/oxygen.html

[That was the first thing I found with Google and searching for "oxygen saturation in water by temperature", so there may be better ones available (like one that actually IMPLEMENTS that calculation, perhaps?).

And, yes I do see that it can be difficult to achieve 10ppm at that temperature - not just difficult, but darn close to impossible, and should you achieve such a level of oversaturation (140% or so), you'd probably end up with dead fish anyways, unless you achieve it by having a high pressure in air above the tank - a good seal on the tank would be necessary to cope with 1.4 ATM pressure. Make sure you have a good quality tank too, with good seals on the corners, as the extra pressure will make it more prone to bursting at the corners [and extra thick glass would probably be necessary too].

--
Mats

[MatsP]

To get 10 ppm at 100% saturation, you need a temperature of around 15'C, all according to the formula on the page I linked to (I copy'n'pasted the formula for Excel and played with the results from that page). 29'C gives around 7.7 ppm at 100% saturated.

--
Mats

[racoll]

like one that actually IMPLEMENTS that calculation, perhaps?

Your wish is my command.....

http://www.fivecreeks.org/monitor/do.html


(Scroll down to bottom for calculator)

[coelacanth]

Peroxide reactors can be very effective at raising DO levels. One commercial unit is caled the Oxydator http://www.growell.co.uk/p/1113/The_Oxydator.html
The Oxy-Plus they refer to is just Hydrogen Peroxide. You can also find details on how to make one of these in "Enjoying Cichlids" from Cichlid Press, edited by Ad Konings.

[Sinatra]

G'day

My humble apologies.10 was not the correct number and as already stated it should have been 6-7ppm. My mind plays tricks on me when it comes to numbers

No I am not trying to do the near impossible and saturate the water with oxygen by using an increased partial pressure and forcing it into the water. Although it got me thinking that it may be possible if the silicone holds. BUt I agree with you it would probably cause oxygen toxicity in the fish and lead to all sorts of problems.

Hmmmm the Oxy-plus sounds very interesting. I will have to dig out my copy of "Enjoying c*****ds" and have a look at what Ad has to say on the subject. Does anyone use one of these?

Does anyone else have any ideas on how to increase the oxygen content to maximum permissible levels? (Excluding of course powerheads)

Thanks again for everyones input

[pleco_breeder]

I looked into this option myself several years ago, and every once in a while, someone else will ask about the possibility. I decided to contact one of my old sales reps to ask about it. The response, plain and simple, was that Ozone cannot be expected to have a consistent effect on oxygen level. However, it can lower the BOD (Biological Oxygen Demand). In the end, this same effect can be had by using a UV sterilizer, and at a lot less expense.

Larry Vires

[racoll]

Larry, how does the UV unit reduce BOD? Just by killing bacteria?

[blueguava]

With a high quality UV Sterilizer you can drastically reduce the amount of free floating microscopic water borne bacteria, parasitic, fungal, viral, algae, and other unfriendly pathogens out of aquarium water by exposing it to UV light. This ultimatly reduces your bio load, however I have always used 3x the recommened flow rate to ensure good exposure to the UV. eg: manufacturer rating 18W 1800LPH I would use that on a maximum 400L tank with a tank return rate of 600LPH.

I have not had a disease out break since using UV (2 years) and it helps keep your water clear.

Regards
Gavin

[DiabloCanine]

Simple solution, plants....DC

G'day

Most of us have tried to increase the oxygen concentration in our cat tanks. This is often done via powerheads.

But I was wondering if people use other methods?

One method is to possibly use ozone. (?) I now it is used in saltwater aquaria.

Does anyone use it in freshwater?
Does it work?
What were the results when you used it?
What equipment did you use and how was it all hooked up?

Does anyone use something else? (Other than air bubbles/water falls/powerheads)

Thanks very much Sinatra

[MatsP]

Simple solution, plants....DC

I don't believe this is a good solution - yes, plants give of oxygen during the day. But, they also take up oxygen during the night. So you get more oxygen during the day, but at night, the oxygen levels are lower than they would have been without plants.

--
Mats

[Sinatra]

G'day

I looked into the use of plants and this is one problem I found . Although there is one type of plant(s) that does not consume oxygen when the lights go out. I am sorry but I don't know where I read this, but I asked for some of these plants at some wholesalers at the time, and was met with some very blank looks so I gave up on this possible solution.

Re: the oxygen generator.

I had a look at Ads book and he uses a lead or silver thread as a catalyst.
Also where do you buy "lead or silver thread"?
Does the lead thread cause any health problems in the fish?
Has anybody set one of these up?
What effect does it have on Dissolved oxygen levels?

It could be a much cheaper method of delivering a high Oxygen level to the fish and each batch will last about two weeks. (Well cheaper than an ozone generator for every tank.)

What are your thoughts, or do I just concede defeat and stick to using lots of powerheads and the fish just get what they get.

Thanks everyone for your input It is greatly appreciated

[MatsP]

One question that I'm not sure if you've answered or not is what your DO levels are right now?

What I'm trying to say is: Are you actually seeing a problem with DO levels, or are you trying to "fix" something that isn't actually broken?

Sure, to get 100% saturation on DO levels, you need A LOT of water movement, but you should get to around 90% without too much difficulty. You do obviously need to have some sort of method to move/disturb the surface water - spray-bars from filters/power-heads and air-stones all do this.

Air-stones is the least expensive method, but power-heards shouldn't cost you very much either.

--
Mats

[Waldo]

Oxygen 0^2
Ozone O^3

Like mentioned before it is a great way to break some expensive things. Hydrogen Peroxide would probably be a more reliable source of oxygen however it will dramatically flux the pH. I've used it when breeding corys because of it's properties.

[coelacanth]

Re: the oxygen generator.
I had a look at Ads book and he uses a lead or silver thread as a catalyst.
Also where do you buy "lead or silver thread"?:

Any craft centre, jewellery repair workshop, bespoke jewellery workshop etc. etc. should be able to provide you with a tiny piece of silver.

[Dinyar]

Keeping your aquarium clean reduces biological oxygen demand and can make a big difference to O2 levels.

A well-balanced planted aquarium can also make a huge positive contribution to O2 levels. O2 created during the day should be well in excess of O2 depletion at night.