The best hobby one I found was the Dupla O2 test kit. Not sure they are made anymore.
O2 level
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damsels are not mean
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they seem to be ok actually
aquatimeFL
New Member
Any sort of air stone, or waterfall will work. I know many aquarists just don't want to use them for many reasons.
1. many people don't like the sight of bubbles or microbubbles air stones in the main aquarium.
2. bubbles pop and create salt creep
3. waterfalls are noisy. They also create splashing resulting in salt creep
For those with small aquariums, don't want air stones or don't have sumps, the last resort is using wavemakers. However, they just don't oxygenate well enough to say there is a healthy amount of dissolved oxygen in an aquarium to support a healthy ecosystem. It's like severely under fertilizing plants. They will still grow without fertilizer, but just look terrible and have health problems and grow extremely slow. The same with low Dissolved oxygen levels in Aquariums. Fish and corals/plants are living but struggling.
If someone doesn't have a sump and wants to do something other than wavemakers:
1. get an air stone for moderate Oxygenation
2. get a canister filter and attach the Multi-Venturi by growgreenie. for High Oxygenation
Canister Filter+ Multi Venturi......Then you can filter and Aerate at the same time
there is a sump version and also an aquarium version that runs off a canister filter into your main aquarium.
www.GrowGreenie.com
this is the canister filter version: It is used mostly in Freshwater tanks, but can also be run in salt. However, that's why there is a sump version for saltwater setups utilizing a sump.
aquatimeFL
New Member
Hi damsels.....thanks for the comment. If you are saying that you strictly just use wavemakers or another method for surface movement only then I Would love to know what your temp and mg/L of dissolved oxygen levels are in your aquarium. I'm very interested what others are recording in their data testing
DavidinGA
Active Member
Since no one has mentioned it, I'll chime in...
The best means of introducing natural additional O2 is by way of a refugium or algae scrubber. If you were to check your O2 levels in your tank you'd find that O2 levels are highest during the times the lights are on and lowest of course when the lights are off. Coral and algae in the dt both produce O2. Lights off = no O2 production.
Run a fuge or algae scrubber 24/7 or on opposite light schedule from your DT and you'll see a nice uptick in O2 levels.
The best means of introducing natural additional O2 is by way of a refugium or algae scrubber. If you were to check your O2 levels in your tank you'd find that O2 levels are highest during the times the lights are on and lowest of course when the lights are off. Coral and algae in the dt both produce O2. Lights off = no O2 production.
Run a fuge or algae scrubber 24/7 or on opposite light schedule from your DT and you'll see a nice uptick in O2 levels.
DaJMasta
Well-Known Member
I'd like to know where you're getting your information, both conceptually and what measurement conditions and procedure, because simply put: the information I've seen available on what are normal levels of oxygenation does not match your claims and my own experience and measurements do not match your claims.
8mg/L DO levels are only observed in the uppermost layers of the warmer climates of the natural ocean, and while the creatures we keep are generally from this zone, it is by no means a consistent level over the day or over the year, there are substantial, daily deviations and seasonal changes that don't go far beyond the saturation point but often do dip below it. Studies that have been done to quantify coral calcification rates and monitor fish presence/behavior typically put the 'danger zone' where DO is problematic at 4mg/L or below - I'm seeing reports of fish kill events at 1.4-1.8mg/L and only at substantially elevated temperature ( https://pubmed.ncbi.nlm.nih.gov/21039501/ ), as well as studies showing that 160% DO saturation offers no benefit to calcification whereas the growth rate is hindered at only far lower than saturation levels (30% in this experiment https://journals.biologists.com/bio...l-calcification-under-daily-oxygen-saturation )
Your arguments also seem to be entirely ignoring the churning effect of sump systems and skimmers, both of which are very prominent in the hobby. It will be the rare reef tank that doesn't have a sump (with drain line aeration), a skimmer (with the venturi oxygenation you seem to be promoting), or an algae scrubber or refugium offering photosynthetic DO production, maybe with additional aeration from water agitation, so even if surface agitation alone was inadequate (which I don't believe even your posted measurements show, given that the threshold for problems seems to be at or below 4mg/L for reef systems), a typical system will have at least one additional method of increasing DO through gas exchange.
I broke out the YSI 556 and measured my two systems as an example. My reef tank is an AIO with no sump (no aeration from falling water), but a reasonably powerful skimmer for the size of tank and a very small algae scrubber (which was harvested earlier in the day and had been off for two hours at time of measurement), and my breeding system is three 10 gallon tanks plumbed together (decent amount of drain line aeration), with low flow in every section, low surface agitation on average, no skimmer, and a refugium that had again been off for several hours at time of measurement. Both systems are pretty heavily overstocked for conventional wisdom, so the consumption of DO is likely higher than an average system, but my DO measurements speak for themselves (third line down, in mg/L), though I could use a new pH probe (this one reads low), and probably need to recalibrate my conductance probe (low salinity reading).
Jay Hemdal
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Just in case folks aren’t aware - “aeration” should be read as “gas equalization”. People tend to equate the term with “adding oxygen”. Two other vital actions take place with good aeration: reducing excess carbon dioxide and balancing nitrogen saturation. 110% oxygen saturation is great, but 110% nitrogen saturation will kill all your fish.
Jay
Jay
aquatimeFL
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Hi DajMasta. Thank you for your input and response. My response was to someone saying that "all you need is surface agitation" for sufficient dissolved oxygen levels. I was making the point that's not true. Out of all the methods I have tested, surface agitation is the worst at dissolving oxygen. You clearly say you are using a churning sump and skimmers on your set up. That is not what I was writing about and the original statement someone wrote did not include those methods. It was about just surface agitation. Most people assume surface agitation means flow nozzles or wavemakers. Please, I invite you to turn off your skimmer and sump and just use your wave makers and then retest your Dissolved Oxygen. Not everyone in this hobby has a skimmer and I'm sorry I didn't clarify that.I'd like to know where you're getting your information, both conceptually and what measurement conditions and procedure, because simply put: the information I've seen available on what are normal levels of oxygenation does not match your claims and my own experience and measurements do not match your claims.
8mg/L DO levels are only observed in the uppermost layers of the warmer climates of the natural ocean, and while the creatures we keep are generally from this zone, it is by no means a consistent level over the day or over the year, there are substantial, daily deviations and seasonal changes that don't go far beyond the saturation point but often do dip below it. Studies that have been done to quantify coral calcification rates and monitor fish presence/behavior typically put the 'danger zone' where DO is problematic at 4mg/L or below - I'm seeing reports of fish kill events at 1.4-1.8mg/L and only at substantially elevated temperature ( https://pubmed.ncbi.nlm.nih.gov/21039501/ ), as well as studies showing that 160% DO saturation offers no benefit to calcification whereas the growth rate is hindered at only far lower than saturation levels (30% in this experiment https://journals.biologists.com/bio...l-calcification-under-daily-oxygen-saturation )
Your arguments also seem to be entirely ignoring the churning effect of sump systems and skimmers, both of which are very prominent in the hobby. It will be the rare reef tank that doesn't have a sump (with drain line aeration), a skimmer (with the venturi oxygenation you seem to be promoting), or an algae scrubber or refugium offering photosynthetic DO production, maybe with additional aeration from water agitation, so even if surface agitation alone was inadequate (which I don't believe even your posted measurements show, given that the threshold for problems seems to be at or below 4mg/L for reef systems), a typical system will have at least one additional method of increasing DO through gas exchange.
I broke out the YSI 556 and measured my two systems as an example. My reef tank is an AIO with no sump (no aeration from falling water), but a reasonably powerful skimmer for the size of tank and a very small algae scrubber (which was harvested earlier in the day and had been off for two hours at time of measurement), and my breeding system is three 10 gallon tanks plumbed together (decent amount of drain line aeration), with low flow in every section, low surface agitation on average, no skimmer, and a refugium that had again been off for several hours at time of measurement. Both systems are pretty heavily overstocked for conventional wisdom, so the consumption of DO is likely higher than an average system, but my DO measurements speak for themselves (third line down, in mg/L), though I could use a new pH probe (this one reads low), and probably need to recalibrate my conductance probe (low salinity reading).
All tests were showing the results in Dissolved Oxygen by a single method by itself. Here is how the method works. Turn all the other stuff off!!!! one by one test each device and then you will know how well surface agitation, an air stone, skimmer or anything else works by itself. You can't say surface agitation gives you sufficient oxygenation if you have a skimmer and sump or other pumps running too. That would be a flawed experiment.
The experiment method ran one thing at a time for a 24 hr period and then took the results in multiple aquariums.
I will include your testing in this too. The one that matched my temp at 26C
1. wavemakers, flow nozzles only @26C 5.8 mg/L. that is not a good DO level
2. air stone only @26C 6.8 mg/L would you agree that is pretty good? I think that is decent.
3. Your setup with skimmer, wavemaker and waterfall sump pump @ 26C 6.77 mg/L was this at night or day? looks like your lights are on full? bc if its day time then its guaranteed even lower at night when lighting is off or on night mode
4. Multi venturi only @ 26C 7.9 mg/L That's excellent considering the saturation point is 8 mg/L at that temp..... and it didn't change or fluctuate day or night.
I was trying to keep it short in my original post so I didn't go over all this stuff. "8 mg/L is the standard" I'm talking about commercial industries that raise fish for farming, hatcheries, Mote Aquariums etc. Trust me that they aren't running DO in the 5-6 range. But most hobbyists do because they don't have the tech to reach near saturation levels. And there are a lot of people out there that struggle to get their Dissolved Oxygen up so I'm offering them some info on a new tech that can do that for them. The Multi Venturi keeps the Dissolved oxygen levels pegged at almost the saturation point no matter what time of day or what the temp of the water is. Some people struggle with extremely low levels at night, but adequate levels by day. If you visibly have a lot of Algae and plants then sure, your oxygen might be great during the day for your fish, but then at night when all the algae and plants start consuming oxygen your fish struggle. And maybe you personally don't have too much algae, but someone else does and their water quality goes down from lower oxygen. But hey, I hope you can agree that the higher the Dissolved Oxygen levels in any aquarium the healthier the fish and environment? I would prefer 7.9mg/L of 6.7mg/L and I'm sure every commercial fish farmer that knows the science and data would too.
I agree with you that skimmers and sumps are good methods for oxygenating. However, some people may not have the right equipment or a lot of stuff on the market is loud and splashes and they want a quieter options.
Anyway, Just wanted to share the method you wanted to know I used and to also thank you for your message!
Your setup and Aquariums look pretty cool. keep up the good work and happy reefing!
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DaJMasta
Well-Known Member
One of the more important things I'm contesting is this first assertion - that 5.8mg/L is somehow a dangerous DO level. This is a commonly reached DO in the wild, and I have not seen a level comparable (say, 5-6 mg/L) to be linked to stress, coral calcification problems, fish illness or weird behavior, etc. So even if surface agitation does the least for encouraging gas exchange, it is still sufficient - at least according to all the tests I've seen - to maintain a healthy tank.
The next point, that commercial aquaria and research institutions don't target 5-6mg/L DO levels, could be the case, but I haven't seen nor heard of any discussion of it. I would be interested to hear their reasoning for where it's kept, especially if intentionally near saturation - whether to have more room as a buffer in case there was a circulation or gas exchange problem, whether there are specific organisms that benefit from it, or whether it's a side effect of the gas exchange required to remove CO2 and keep pH up. I know that in commercial fish farms aeration and dissolved oxygen is critically important, but not because the animals need a point near saturation for health or growth, but because the stocking in the tanks where they live is so high that without it they would use up all the DO and die in very short order.
I also disagree with the assertion that there are a lot of people that struggle with dissolved oxygen - the first post in this thread is fairly telling in that many aquarists are simply unaware of their level or potential targets, and while I think there are occasionally situations where low dissolved oxygen in a tank can be a problem in an aquarium, I think they are few and far between for previously mentioned reasons (that various common equipment is more than adequate to maintain consistent DO levels). In fact, I've heard dissolved oxygen mentioned most frequently in the now-passe discussions of deep sand beds more than I've seen it mentioned in regard to water DO levels.
In any case, I'm not arguing that an airstone or similar wouldn't raise it, or that a level close to saturation is a bad thing, I'm arguing that your threshold where you say it's problematic is way too conservative (and aren't backed up by any studies I've seen) and that the assertion that hobbyists need to do something about it is simply not true in the majority of setups. It helps to be educated on the subject and have a solution in mind if it comes up, but I don't think there's evidence that it comes up much or that there are a significant portion of systems in operation which don't already have tools to address the problem built in before considering dissolved oxygen.
It's now evening for me, and my lights have been off a couple hours, so here's my readings for the same two tanks:
6.54mg/L DO in the breeder rack (no change in circulation, no lights on top to tanks, but now a light on in the refugium bottom level)
5.22mg/L DO in the main system (pumps on only) after about an hour of no pumps at all (I turn them off at night to collect spawn), then I turned the skimmer on, waited ten minutes, and read 6.38 mg/L DO. Because of the way this sensor works, you want water flow across it to prevent it from locally depleting the oxygen around the sensor head itself, so I didn't do any testing in stagnant water (though that is also an unrealistic scenario for a reef tank).
I personally aim for higher than that 5.22mg/L reading, but it was in effectively worst case circumstances aside from equipment failure or lengthy power outage, and even in my overstocked tank it's a safe level. No visible stress, no abnormal behaviors, no polyp retraction, etc., and it recovers very quickly when you switch on the skimmer.
aquatimeFL
New Member
Hi again DajMasta,
Look, I'm not sure why you are saying I said that 5.8 mg/L is a dangerous DO level. I never stated that anywhere. I said "surface agitation is the worst at oxygenating aquariums out of all methods" I never said anything about it being dangerous. Or was trying to put anyone down for those numbers. Yes, you are correct that sometimes those levels drop to that in the wild, but that doesn't mean that is great for fish health. You keep saying that it is sufficient, but I'm not arguing against that at all. I never said it was insufficient. I said it gave the lowest readings on a Dissolved Oxygen meter compared to Air stones and waterfalls. So maybe you are taking this all the wrong way and I'm sorry you are reading into it wrong somehow.
you said "I know that in commercial fish farms aeration and dissolved oxygen is critically important, but not because the animals need a point near saturation for health or growth"
It absolutely improves growth rate and health, less disease, and less bad bacteria in the water. Thats why they do it commercially. You can find studies everywhere online published by government agencies and Universities about water quality and dissolved oxygen. The higher you can raise your dissolved Oxygen the better. Everything improves. Fish growth rate, feed rate, good bacteria, nitrogen cycle, quicker decay, less disease. I can go on and on. So yes, you can sit at the sufficient 5.22 mg/L you are getting in your aquarium at night. But almost every study shows that 5 mg/L is the minimum for fish health. Anything under that and its considered unhealthy. That means your 4% DO away from what is considered an unhealthy environment at night time. I'm in no way trying to criticize you or your test and numbers, but it sound like you have a problem with me saying that a lot of hobbyists struggle with DO. IMO They absolutely do. I talk to countless people who ask "why is my water always cloudy"?. "My fish aren't active and stay at the top of my tank". "Why will my fish not reproduce very often?" Or "I have constant disease problems".
High Dissolved oxygen can help them fix a lot of issues and yes, it is a problem most people don't know what their dissolved oxygen levels are. So maybe some people would like a product that helps exchange gases so efficiently and quickly. Then they wont ever worry about it or need to test it.
you said "I'm arguing that your threshold where you say it's problematic is way too conservative (and aren't backed up by any studies I've seen) and that the assertion that hobbyists need to do something about it is simply not true in the majority of setups.
I never set a threshold anywhere in my statements. I said 5.8 was not a good level compared to other methods levels. I didn't set a threshold and I feel like you are being unfair. Let's put it this way. If the saturation point of water is 8mg/L @ 26c and we will call (4.9 mg/L a not optimal healthy environment) like almost every published paper says. It must be above 5mg/L to be considered optimal and Healthy of which you are .22mg/L away from being in that zone for most of the night cycle. I know my Aquariums and all the test Aquariums, all improved dramatically once we started achieving near saturation point DO. Fish get extremely active. They eat at a much faster rate. I haven't seen cloudy water in over a year. It's all crystal clear and we only do water changes every several months. There is no need to do constant water changes but to just top off because there are no issues what so ever. For the longest time, fish were rarely reproducing when the DO was in the 5 mg/L range. Now they reproduce faster than we can keep up with. Nothing randomly ever dies anymore. Fish just use to get sick and die once in a while for no reason. Even though they weren't old.
My thoughts are I have been on both sides of the Dissolved oxygen levels and I'm never going back to low and mid 5 mg/L in my personal aquariums. That is considered barely optimal environment by every published paper out there. Most University studies said 80%-100% Dissolved Oxygen levels were the healthiest environments. That would mean 6.4mg/L @26c is the lowest you would want to go if you wanted the" healthiest environment". Studies also show fish in a 60% DO environment grew much slower. That would be the 5mg/L range.
Look, I'm glad your setup and way of oxygenating is working for you. I'm glad to hear that. But maybe you would see some cool changes in your aquarium that always ran at 90%+ Dissolved Oxygen levels? What if it never dropped below 7.5 mg/L day or night? You might see a lot of exciting and fun changes in your cool aquariums, fish, and corals. less maintenance?
Thanks again for your comments and time. I just really hope you don't think that I was telling people 5.8 mg/L DO was dangerous. If that is what you thought I was getting at then I apologize. Dangerous is definitely in the low 4's and 3's
cheers
Randy Holmes-Farley
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For those who have not read them, Eric has some nice articles on measuring O2 impacts by various means:
