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Oxygenation via plants

Soilwork

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22 Nov 2015
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Has anyone with a dissolved oxygen meter ever measured the oxygen levels in the water column in a heavily planted tank that does not rely on surface agitation or aeration as other forms of oxygenation?
I’m curios to see how they compare?
 
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I have a planted shrimp bowl that has complete coverage of carpet plants and floaters that block off surface gas exchange. I can see heavy pearling when sun light hit the bowl in the afternoon when pH rises from 7.5 to 8.8 at the peak indicating CO2 is stripped to 0.2 ppm based on kH pH table, and DO must be up high even without measurement. There must be enough DO reserve for the remainder of the day as I’ve never observed my shrimp and snails grasp for air outside the 4 hour sun light period.
 
Hi all,
Has anyone with a dissolved oxygen meter ever measured the oxygen levels in the water column in a heavily planted tank that does not rely on surface agitation or aeration as other forms of oxygenation? I’m curios to see how they compare?
I think @Geoffrey Rea did it fairly recently. There is also <"Canford Park">, which would fulfil those criteria even though the "planting" was unconventional.

cheers Darrel
 
Hi all, I think @Geoffrey Rea did it fairly recently. There is also <"Canford Park">, which would fulfil those criteria even though the "planting" was unconventional.

cheers Darrel

Hi Darrel

when you mention that most keepers need, oxygen, plants and time to be successful. Do you think that the oxygen part from healthy plants is enough to not need other forms of aeration?

i want my plants to provide the o2 for the system during the day and use an aerator at night. If I use the aerator during the day the plants get less access to co2 though it is a constant supply.

this means they grow slowly and leak less oxygen in to the substrate which means less microbial activity in the substrate.

If you are going to use plants, wouldn’t it be better to trying to maximise co2 so that they provide more o2?

thanks

CJ
 
Broader answer to this topic in this journal

Starts at post #118 to #133

Further discussion in Maximising dissolved oxygen

Thanks Geoffrey.

Ive been using a bubbler and then a bubble wall for a while. I wasn’t using a filter. This has positives and negatives as I’m sure you are aware.

keeping pumps external to the water must be better for fish. The bubbler produces fine bubbles which maximises and increases o2 availability and keeps it as well as co2 stable reducing ph swings. The fish are more lively as well as the shrimp and snails.

What I don’t enjoy about this set up is that the bubbler keeps particles that have been kicked up suspended. The noise another con and the spray causes quicker evaporation even with a cover. If you don’t have enough plants mass the rapid microbial activity tends to favours algae.

Despite no addition of fertilisers I am constantly removing duckweed which looks perfectly green and healthy with long roots. So I know the plants are limited only by co2. Don’t get me wrong, they grow, just much slower with aeration.

My thoughts are that they substrate becomes healthier in terms of biofiltration and symbiotic microbial relationships with plants if the rhizosphere is well oxygenated and higher co2 lends itself to this.
 
Hi all,
Do you think that the oxygen part from healthy plants is enough to not need other forms of aeration?
I would always have some form of water circulation, but I have tanks that really are full of plants, so there will always be the possibility that oxygen levels may become depleted at night. It is "belt and braces" really, I'd rather have insurance, some usually two filters on larger tanks.

cheers Darrel
 
Hi all, I would always have some form of water circulation, but I have tanks that really are full of plants, so there will always be the possibility that oxygen levels may become depleted at night. It is "belt and braces" really, I'd rather have insurance, some usually two filters on larger tanks.

cheers Darrel

Hi Darrel

I’m using circulation currently. Bubble walls also tend to create quite a lot of water movement.

I understand the belt and braces reasoning but my question is about plants and their ability to saturate the water column in a heavily planted tank. I will always use aeration at night. If you can get pearling plants in a heavily planted aquarium with high light. Would this not suggest that an aerator is not necessary as the plants have saturated the water column with oxygen?
 
Hi Darrel

I’m using circulation currently. Bubble walls also tend to create quite a lot of water movement.

I understand the belt and braces reasoning but my question is about plants and their ability to saturate the water column in a heavily planted tank. I will always use aeration at night. If you can get pearling plants in a heavily planted aquarium with high light. Would this not suggest that an aerator is not necessary as the plants have saturated the water column with oxygen?
It depends on the stocking and the amount of pearling.

In my zero tech shrimp bowl, pearling sustains for several hours when sunlight hit the bowl in the afternoon. Pearling is an indication of O2 saturation because oxygen can no longer dissolve in water passed the Saturation point. Because I provide no circulation and the surface is blocked by floaters, there is minimal surface gas exchange. O2 is largely preserved and slowly consumed by shrimp, snails and micros throughout the day in exchange for CO2 plants consume during photo period. The O2 cycle is complete as the bio load of inverts is low.

If I had low light, minimal pearling or heavy stocking with fish, O2 cycle will be incomplete and supplemental aeration is needed. This is the case with my high tech tanks in which pearling rarely occurs, light is medium, and fish stocking is so heavy that without supplemental aeration, O2 will soon be depleted at night.
 
Hi all,
Bubble walls also tend to create quite a lot of water movement.
They do.
If you can get pearling plants in a heavily planted aquarium with high light. Would this not suggest that an aerator is not necessary as the plants have saturated the water column with oxygen?
Yes, it will also have saturated the internal spaces of the plants with oxygen.

You also have to think about replenishing CO2, water circulation will help do that. I just think that having water circulation makes aquarium management easier.

cheers Darrel
 
Recently, I've introduced UV lamps in some of my tanks. Not as a remedy when trouble occurs but permanently, as a precaution.
I think it decreases oxygen demand within the water column. So, in a way, it may serve as an alternative to aeration. What do you think about it?
 
Recently, I've introduced UV lamps in some of my tanks. Not as a remedy when trouble occurs but permanently, as a precaution.
I think it decreases oxygen demand within the water column. So, in a way, it may serve as an alternative to aeration. What do you think about it?

Sounds like a bit of a stretch to me, but a good excuse to buy a DO meter to test the theory!
 
a good excuse to buy a DO meter to test the theory!
I appreciate your commitment to cover the cost! :clap:
Sounds like a bit of a stretch to me,
Why so? Proliferation of microbes in the water column is a bad thing. If I kill them, more oxygen is saved for plants, fishes - if I had any - and benthic microbes.
You think the difference in oxygen demand originating in water column is negligible?
 
I appreciate your commitment to cover the cost! :clap:

😂 I've come so close to buying one myself on a number of occasions, but they are priced to a little to out of reach for the minimal number of tests I'd like to perform.

Why so? Proliferation of microbes in the water column is a bad thing. If I kill them, more oxygen is saved for plants, fishes - if I had any - and benthic microbes.
You think the difference in oxygen demand originating in water column is negligible?

I do suspect that the amount of oxygen demand in the water column is negligible compared to the amount of oxygen produced by the plants, yes, particularly in your tank where you have no livestock, and do 50% water changes. There is also the consideration that you don't run any type to filter to remove solid organics, so I suspect those organic particles are going to get processed by microbes somewhere in your tank no matter how thoroughly you try and remove them from the water column.
 
There's a Cheap DO pen that keeps dropping to £50 on ebay that I've nearly pulled the trigger on repeatedly, just because I'd love to know the O2 profile across the day. But as you say, not worth it for the small number of tests I'd do.
 
those organic particles are going to get processed by microbes somewhere in your tank no matter how thoroughly you try and remove them from the water column.
Of course, the total oxygen demand does not decrease. The difference is that within the water column, redox is increased, and also, that the upper layer of the substrate stays in contact with well-oxygenated water, so it too remains oxygenated. It could be said that the oxygen consumption is pushed below the water column. And that is an effect I consider important.
 
Of course, the total oxygen demand does not decrease. The difference is that within the water column, redox is increased, and also, that the upper layer of the substrate stays in contact with well-oxygenated water, so it too remains oxygenated. It could be said that the oxygen consumption is pushed below the water column. And that is an effect I consider important.

In an effort to increase the consumption of organics in my 5' tank , I'm contemplating running a venturi-enabled powerhead. My tank is 60.5" x 25.3" x 21.7"; I'd run the powerhead along the back with a length of silicone hose attached to it. I have no problems with O2 in the tank, despite living at 6600ft (and resultant lower atmospheric pressure), because of the amount of water coming out of the two outlet pipes relatively close to the surface of the water and the surface turbulence this causes.

However, I'm always interested in trying to improve things and I wonder if a 300gph powerhead + venture could oxygenate the water to the point that I'd notice a decrease in BBA. I have very, very little right now, but, I'd like to see none. I do a 60%+ water change once a week but think the powerhead running for a few hours every night could help as well.

Thoughts?
 
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