Inline oxygen dosing, good or bad idea?

[Chuunofish]

Hi happy new year all may 2022 bring all that you wish for. I am just starting a planted discus tank and trying to minimise the number of pipes in the tank, I am running oase biomaster 600 and 350 on a 350ltr tank with co2 but need to boost nightime oxygen levels so was looking at an inline airpump if there is such a thing as I don't want airstones in the tank. Discus like slow moving water so options are either air or raising the spray bar our of the water to aid surface agitation which doesn't look or sound great. Any ideas would be welcome.

Thanks and regards

 

[hypnogogia]

I doubt whether you’ll get an air pump that has enough pressure to work with an in-line diffuser. Good Surface agitation will be your best bet.

 

[Maf 2500]

How about an airstone hidden at the back and on a timer only to come on at night when you can't see the bubbles?

 

[erwin123]

If you are looking at a device that generates oxygen bubbles you could look at a Twinstar Nano.

 

[Jas_Nagra]

I had this dilemma recently and just buried the airstone under an area of gravel. The bubbles are not very fine as a result, but the airstone is out of sight. I also put it on a timer to come on about 2hrs after lights out. There are some quite tidy looking airstones (white ceramic discs), but they still clutter up the tank.

 

[zozo]

You could go for an air venturi on the filter outlet... Then if it needs to switch off during the day then use a 4-way solenoid that closes the venturi air inlet when CO² opens.

 

[Andy Pierce]

The version I heard is that an airstone doesn't have any meaningful impact on oxygen levels from the air bubbles diffusing oxygen into the water column as such, but rather improves oxygen gas exchange by causing water surface agitation. What makes you think you need more oxygen in the water at night?

 

[Conort2]

Is there any particular reason you need to boost oxygen at night? Two canisters providing a slight ripple at the surface should give you more than enough oxygen.

 

[zozo]

AFAIK the main reason why it is theoretically advised to run an airstone at night is to get quicker to a lower CO² level during this period.

 

[aquagenetics]

if its just for when the lights are off in the night i would just raise my outlet.

 

[arcturus]

Hi happy new year all may 2022 bring all that you wish for. I am just starting a planted discus tank and trying to minimise the number of pipes in the tank, I am running oase biomaster 600 and 350 on a 350ltr tank with co2 but need to boost nightime oxygen levels so was looking at an inline airpump if there is such a thing as I don't want airstones in the tank. Discus like slow moving water so options are either air or raising the spray bar our of the water to aid surface agitation which doesn't look or sound great. Any ideas would be welcome.

First question: why do you need to increase oxygen levels? Are the fish showing distress during the night? Or does the pH level remain high?

You can increase the oxygen level by increasing surface agitation, which increases the overall surface area and promotes gaseous exchanges that enable more oxygen to dissolve.

An inline air pump will not increase surface agitation - and you would need a specialized air pump to deliver the necessary working pressure to the inline diffuser. Have you considered hiding an air stone under the gravel or behind the hardscape? An alternative is adding a skimmer (possible with a venturi valve) to operate during the night or adding a circulation pump to increase surface agitation. The latter has the advantage of helping with CO2 distribution during the photoperiod.

 

[arcturus]

Is there any particular reason you need to boost oxygen at night? Two canisters providing a slight ripple at the surface should give you more than enough oxygen.

To reduce or reset CO2 levels and to counteract plant respiration outside the photoperiod. Some tanks have a very low CO2 degassing rate if surface agitation is not increased outside the photoperiod. You might find that the surface agitation required to promote gaseous exchange and stabilize CO2 levels during the day is simply not enough to degass the tank during the night.

 

[Chuunofish]

I doubt whether you’ll get an air pump that has enough pressure to work with an in-line diffuser. Good Surface agitation will be your best bet.

I was debating using a small compressor as used for airbrushing, good quality units produce very clean air.

 

[Chuunofish]

I had this dilemma recently and just buried the airstone under an area of gravel. The bubbles are not very fine as a result, but the airstone is out of sight. I also put it on a timer to come on about 2hrs after lights out. There are some quite tidy looking airstones (white ceramic discs), but they still clutter up the tank.

I may just end up with doing this.

 

[Chuunofish]

You could go for an air venturi on the filter outlet... Then if it needs to switch off during the day then use a 4-way solenoid that closes the venturi air inlet when CO² opens.

Was debating modifying a stainless lilypipe to include a venturi similar to the design juwel use

 

[Chuunofish]

First question: why do you need to increase oxygen levels? Are the fish showing distress during the night? Or does the pH level remain high?

You can increase the oxygen level by increasing surface agitation, which increases the overall surface area and promotes gaseous exchanges that enable more oxygen to dissolve.

An inline air pump will not increase surface agitation - and you would need a specialized air pump to deliver the necessary working pressure to the inline diffuser. Have you considered hiding an air stone under the gravel or behind the hardscape? An alternative is adding a skimmer (possible with a venturi valve) to operate during the night or adding a circulation pump to increase surface agitation. The latter has the advantage of helping with CO2 distribution during the photoperiod.

I am trying to replicate natural conditions of slow moving water which discus prefer. The target kh is <4 so limited buffering potential. Obviously co2 complicates pH management across 24 hours.

I am still at the design stage but don't want to go through the potentially expensive process of stressed fish. I have used a venturi on a juwel rio 350 rather than an airstone which worked really well.

I may be overthinking the whole thing and may just raise the spray bar and forget lily pipes and Co2 as the plants air mainly crypt, anubias and amazon sword so all quite hardy

 

[arcturus]

I am trying to replicate natural conditions of slow moving water which discus prefer. The target kh is <4 so limited buffering potential. Obviously co2 complicates pH management across 24 hours.

I am still at the design stage but don't want to go through the potentially expensive process of stressed fish. I have used a venturi on a juwel rio 350 rather than an airstone which worked really well.

I may be overthinking the whole thing and may just raise the spray bar and forget lily pipes and Co2 as the plants air mainly crypt, anubias and amazon sword so all quite hardy

I believe Discus require quite high water temperature. The solubility of gases in water decreases with increasing temperatures. So, in a warm Discus tank you will have less dissolved O2 than in a tank kept at lower temperatures. Combined with CO2 injection, this can create issues that would not exist in lower temperature setups. Moreover, the plants you will have can grow in a “low tech” tank and I also assume the tank will not be heavily planted - or at least I have never seen a Discus tank with a significant plant mass when compared to a high-tech aquascape. So, it is not clear why you plan to inject CO2. Given all of this, I would think twice about using CO2 - it may cause unnecessary headaches without any tangible benefit.

 

[Chuunofish]

I believe Discus require quite high water temperature. The solubility of gases in water decreases with increasing temperatures. So, in a warm Discus tank you will have less dissolved O2 than in a tank kept at lower temperatures. Combined with CO2 injection, this can create issues that would not exist in lower temperature setups. Moreover, the plants you will have can grow in a “low tech” tank and I also assume the tank will not be heavily planted - or at least I have never seen a Discus tank with a significant plant mass when compared to a high-tech aquascape. So, it is not clear why you plan to inject CO2. Given all of this, I would think twice about using CO2 - it may cause unnecessary headaches without any tangible benefit.

Thank you for the advise which is the route I am going to follow