Water surface disturbance and CO2

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Martyn87

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So, I have a low tech heavily planted tank. Lights are on 5 hrs a day. I use excel and have a good fish stock for my co2 sources.

My question is; should I have more surface agitation or less to maintain the carbon sources in the water?

I've read differing stories and wanted to hear others experiences.
 
Before I get to the surface disturbance issue...I would not use Flourish Excel in any tank with fish. This so-called "liquid carbon" is glutaraldehyde and water, and glutaraldehyde is a highly toxic disinfectant used in hospitals to disinfect surgical instruemnts, in embalming fluid, and similar. It is deadly. Even at recommended doses it will often kill some plants, Vallisneria seems especially sensitive. But it only takes a slight overdose to risk killing plants, fish and bacteria. Aside from this, like all substances added to the tank water it gets inside the fish, into their bloodstream and internal organs, and this is without question detrimental to fish. Trump may think it is OK to inject disinfectants into living bodies, but I disagree. o_O

There is more natural CO2 in an aquarium than many realize. Not only is there the respiration of fish, plants and some bacteria species, there is the primary source from the breakdown of organics by bacteria in the substrate. This should be sufficient to balance five hours of light each day.

Now to the surface disturbance issue. In the past it was believed that increasing surface disturbance would drive off CO2 faster. A few years ago, the idea that the reverse may be the case took hold. I looked into this at the time, but those holding the view really had no actual data to support it. I do know that in my fairly well planted low-tech (no diffused CO2 and moderate light) tanks the CO2 does build up during the darkness, to the point that it begins to impact the respiration of fish in the tank. I spotted this one morning with my Corydoras; I increased the surface disturbance from the filter, not a lot, but just so it was rippling at that end of the tank, and the problem disappeared, at least to the extent that the fish no longer respirate heavier in the early morning.

I think Tom Barr's advice here is on the mark--use the response of the plants to assess the balance. Unless your light is quite intense, you should have no detrimental loss of CO2 with only five hours of "daylight" each 24-hour period. It is easy enough to add the other nutrients, but not to excess as this can cause other issues for the plants and again the fish.
 
+1 on Excel. Any chemical used to disinfect heat sensitive medical and dental equipment can't be good for fish! How it was ever discovered to be beneficial for plant growth is a mystery to me. ("hey Egor, lets put sterilizer in the water and see how the plants do.") :dunno:
The question of CO2 relative to surface turbulence and aeration has been debated since I can remember. Planted tank enthusiasts, especially with CO2 systems fear the turbulence and air. Fishkeepers, with or without plants, tend to feel that greater O2 is best for the fish. For awhile, I played with DIY CO2, but tired of it. I only have air where there are sponge filters and the rest is dependent on turbulence. To be honest, I just don't give it much thought...but I would if I saw any signs of distress.
 
+1 on Excel. Any chemical used to disinfect heat sensitive medical and dental equipment can't be good for fish! How it was ever discovered to be beneficial for plant growth is a mystery to me. ("hey Egor, lets put sterilizer in the water and see how the plants do.") :dunno:
The question of CO2 relative to surface turbulence and aeration has been debated since I can remember. Planted tank enthusiasts, especially with CO2 systems fear the turbulence and air. Fishkeepers, with or without plants, tend to feel that greater O2 is best for the fish. For awhile, I played with DIY CO2, but tired of it. I only have air where there are sponge filters and the rest is dependent on turbulence. To be honest, I just don't give it much thought...but I would if I saw any signs of distress.
Sort of like "I wonder if we could make sticky stuff using cow feet"
 
Don't waste your time or money adding CO2. You don't have enough light for it to be of benefit.

Most aquarium plants like a bit of light and if you only have the light on for a couple of hours a day, they struggle. If the light doesn't have a high enough wattage they also struggle. Try having the tank lights on for 10-12 hours a day.

If you get lots of green algae then reduce the light by an hour a day and monitor the algae over the next 2 weeks.
If you don't get any green algae on the glass then increase the lighting period by an hour and monitor it.
If you get a small amount of algae then the lighting time is about right.

Some plants will close their leaves up when they have had sufficient light. Ambulia, Hygrophilas and a few others close their top set of leaves first, then the next set and so on down the stem. When you see this happening, wait an hour after the leaves have closed up against the stem and then turn lights off.

-------------------
Stress from tank lights coming on when the room is dark can be an issue. Fish don't have eyelids and don't tolerate going from complete dark to bright light (or vice versa) instantly.

In the morning open the curtains or turn the room light on at least 30 minutes (or more) before turning the tank light on. This will reduce the stress on the fish and they won't go from a dark tank to a bright tank instantly.

At night turn the room light on and then turn the tank light off. Wait at least 30 minutes (or more) before turning the room light out. This allows the fish to settle down for the night instead of going from a brightly lit tank to complete darkness instantly.
 
Sorry I should have also added that my tank is in room where it also gets direct sunlight for at least 6 hrs per day so coupled with the 5 hrs of LED light I’m on the borderline of algae starting, my Anubias is big and over 5 yrs old but was starting to see a bit of diatom growth until I cut the light back an hour. The plants are growing well but I’ve noticed a slow down in growth and recently upped nutrients to check what the limiting factor is. I’m pretty sure it’s co2, I have a really over filtered tank fx6 and eheim eco 3 both with spray bars and the water disturbance is very high.

Byron given your experience how low was the disturbance when your co2 was getting high?

Noted on the glutamine. I’ll wean the plants off it slowly.
 
For completeness this is the light on the tank, there is a fair bit of power in it and its 7000 kelvin. I only have the one running in here but when i was using a high tech tank previously I used two and the power out of these seemed pretty high.

EHEIM powerLED+ fresh daylight
  • Bright daylight (7.000 K) with full sunlight spectrum
  • Maximum energy efficiency and light output (141 lm/W)
 
Byron given your experience how low was the disturbance when your co2 was getting high?

I cannot do a video which would help illustrate, and it is difficult to describe. But that tank had a canister filter with a spray bar along one end wall. I removed the spray bar and adjusted the spigot of the filter return so it made the water at that end bump up into moving or rolling hills and valleys, if that makes any sense.
 
Thanks Byron yeah I got what you mean. Would a drop checker measure it accurately if I halfed the solution with RO to measure 15ppm CO2? Not sure if any one has tried this. As I understand it low tech shouldn't need any more than that?
 

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