Keeping Oxygen in my tank

[SpyderSpy6]

In my 75 gallon, planted discus tank, I'm having some issues.

I run an inline C02 reactor and injection. I'm trying to make the environment perfect for my discus and for my plants. Water quality isn't the issue, but keeping enough oxygen in my water has been a task.

I was using an airstone 24 hours a day. In order to get the most out of my CO2, I've read that an airstone when the lights are on will realease CO2 which is why you should only run the airstone at night.

I did this, and about 3 hours now my airstone has been off and the fish are sucking wind (it appears to look like). I put the airstone back on because I can't watch them like this.

Has anyone had this issue? What did you do to fix it? What is the best time and way to run my CO2 in cahoots with the airstone?

[RainMan]

I've been told the same... light off... air on. However, I've never heard that they release co2 when the air and lights are on.

The bubbler is used at night to help aid in oxygenation when the plants stop synthasizing. I dont' see why you would need to turn it off during the day.

[MandyL]

You're right, the theory is that during the day when plants are photosynthesizing, they need all the co2 they can get and shouldn't have a bubbler running. At night they don't use up the co2 so the air bubbler is beneficial. However, if it's a question of the health of your discus or your plants, I would definitely cater to the discus. Could it be that you are just injecting c02 too fast?

[RainMan]

You're right, the theory is that during the day when plants are photosynthesizing, they need all the co2 they can get and shouldn't have a bubbler running. At night they don't use up the co2 so the air bubbler is beneficial. However, if it's a question of the health of your discus or your plants, I would definitely cater to the discus. Could it be that you are just injecting c02 too fast?

Oh... yeah, I didn't even think of that. The air is starving the plants of co2.

I was thinking that too... too much co2. Could it also be that the discus are creating enough co2 on their own.. so that the co2 injection really isn't needed as much?

[SpyderSpy6]

To be honest... I didn't realize I could inject too much, too fast in to my water. I have set the CO2 off, just so that I don't waste it. My plants do look healthy but I try to take very good care of them. For now I am going to keep using the airstone.

Is there a way to gradually transition my tank to where it doesn't need the airstone during the day? And if the airstone is releasing the CO2, wouldn't that even out injecting too much? What's the standard way of making my system stable?

One other thing.... Until about 6 months ago, I didn't have this problem. I don't know what I could have changed. My fish became sick and they were gasping and I put the airstone in. Since then, any time I take it out, all of my fish seem to be struggling for air!

Thank you guys for the quick responses!

[RainMan]

Are your plants covering the surface of the water? Is there a gap of air between the surface of your tank and the hood? How many discus do you have? And what's the dimmensions of your tank?

[xoolooxunny]

Maybe upgrade your lighting and ferts for optimum plant growth? with that kind of system the plants should have no problem making enough o2 for the fish. and remember, more co2 doesn't mean less o2 in the water, so dont be afraid of 3-4 bubbles per sec.

[mister]

Water quality isn't the issue.....

I was using an airstone 24 hours a day. In order to get the most out of my CO2, I've read that an airstone when the lights are on will realease CO2 which is why you should only run the airstone at night.

I did this, and about 3 hours now my airstone has been off and the fish are sucking wind ...


I've been lurking on here a while and figured now is as good a time as any to jump in. I've had aquariums for most of my 45 years. I'll post an introduction later.

I've seen a few of your posts on here where things have gone wrong very quickly. I followed the link to your aquarium blog and saw some things I think are a problem.

from your blog;
---------------------------------
"Co2 Injected & ....

* Flourish Excel
* Trace
* Nitrogen
* Phosphorus
* Potassium
* Iron
* Flourish Root Tabs
* Equilibrium

**Water change everyday to every other day... Liquid supplements with every water change, and root fertilizer once a week"
-----------------------------
I've had Discus for years so I'm familiar with their slightly higher attention needs.

A daily water change is way too much. The long list of daily additives certainly isn't helping any either. Your tank is in a near constant state of cycling. I would recommend changing the water no more than once a week and cut back on all the additives. Dosing is fine, but not daily and not at that level. Instead of trying to create perfect water everyday, let your tank stabilize.

As far as your CO2 is concerned, your fish aren't gasping for air, it sounds like they're gasping for water that isn't poisoning them - which it sounds like your CO2 is, because it's set too high. Also, an air stone will help rid the water of excess CO2.

You have a big tank and not many fish - it shouldn't be hard to level it out. I'd recommend cutting way back on trying to control it all, daily.

Just my two cents.

[SpyderSpy6]

My tank is an open top tank. I have 3.4 watts per gallon. I recently messed up my plants and had to start from scratch. They all died during a move. I have the back half of my 75 gallon almost covered and the plants are growing fairly well. I don't expect to see them take off for about a month.

I have 6, 4-5in discus in the tank, and some smaller tetra's, a pleco, and to clown loaches.

I have fert sticks that last 6 months, lined the back of the tank with them about 1 month ago. I use flourish tabs everytime I add a plant as well.

Please let me know if there is anything else needed. I also use a Filstar XP3 that has the CO2 inline, and a UV Sterilizer.

[jman]

water pumps and powerheads work with my africans and just about everything else


http://www.drsfostersmith.com/product/pet_supplies.cfm?c=3578+4585

[ILuvMyGoldBarb]

I am definitly in agreement with mister. My 125 planted tank was high tech and I had Discus in it as well. My CO2 was maintained at roughly 30ppm, and I had a daily dosing regieme to boot. My dosing was, however, not to the recommended levels for a tank like I had, I cut back on those things slightly because of the Discus. I had my CO2 hooked up to the same timer as my lights. This was not the ideal situation, I realize, my CO2 should have come on about half and hour to and hour before the lights and gone off a half hour to an hour before the lights did. My Discus never suffered any ill effects from my routine. I also followed Tom Barrs method of EI dosing. I does my Macro nitrients on Sunday, Tuesday, and Thursday, and my trace nutrients on monday wednessday and friday. Saturday was a day for enjoying the tank and then Sunday was prun, replant and water change day. My Discus did very very well in these conditions. My tank was also understocked as well so keeping things healthy wasn't too difficult.

[ILuvMyGoldBarb]

I have fert sticks that last 6 months, lined the back of the tank with them about 1 month ago. I use flourish tabs everytime I add a plant as well.

Wow, no wonder the fish are not liking the water. If you are dosing the water column you don't need that many plant sticks. With plants it's not a matter of either/or when it comes to feeding from the roots or the water column. All rooted plants are capable of taking in nutrients from the water column and from the roots. While they do have a prefered method of intake, they will take the nutrients from the easiest source. If you are providing all your rooted plants with root tabs then you really don't need to be dosing all that stuff in your tank. However, I would discontinue the root tabs under all your stem plants, they prefer uptake from the water column. All your rosette plants will be fine with the root tabs. But you need to cut back on dosing a lot as well.

[RainMan]

I've been lurking on here a while and figured now is as good a time as any to jump in. I've had aquariums for most of my 45 years. I'll post an introduction later.

I've seen a few of your posts on here where things have gone wrong very quickly. I followed the link to your aquarium blog and saw some things I think are a problem.

from your blog;
---------------------------------
"Co2 Injected & ....

* Flourish Excel
* Trace
* Nitrogen
* Phosphorus
* Potassium
* Iron
* Flourish Root Tabs
* Equilibrium

**Water change everyday to every other day... Liquid supplements with every water change, and root fertilizer once a week"
-----------------------------
I've had Discus for years so I'm familiar with their slightly higher attention needs.

A daily water change is way too much. The long list of daily additives certainly isn't helping any either. Your tank is in a near constant state of cycling. I would recommend changing the water no more than once a week and cut back on all the additives. Dosing is fine, but not daily and not at that level. Instead of trying to create perfect water everyday, let your tank stabilize.

As far as your CO2 is concerned, your fish aren't gasping for air, it sounds like they're gasping for water that isn't poisoning them - which it sounds like your CO2 is, because it's set too high. Also, an air stone will help rid the water of excess CO2.

You have a big tank and not many fish - it shouldn't be hard to level it out. I'd recommend cutting way back on trying to control it all, daily.

Just my two cents.


That all made cents to me... pun intended. :)

[SpyderSpy6]

Thanks mister! I will try that out. I will back off the water changes a little bit then.

[SpyderSpy6]

So what is a good measure to run my CO2? I've heard a 2-3 second bubble is good. Which is what I was doing. I have not set my CO2 up to run with my lights, but I shouldn't have any trouble getting that to work.

The one question that hasn't been answered...

How to I transition my air stone and my CO2 to work together so that my fish are not gasping for air. I've turned my CO2 off for the past 2 days, and I'm about to order and oxygen test kit. Also... how do I measure the level of CO2 in my water? I haven't placed the order yet, so I can add a test kit for CO2, I've just never seen one.

Thanks for all the help!

[RainMan]

I've been reading up on this... I'm in the planning stages of a planted tank. but, I've read a lot and can't remember anywhere it saying to turn off the aeration during the lighting period. If my memory serves me well, plants need o2 as well co2... and it is most important to your fish. I wish I had my book in front of me. But, a quick google and I found this statement, which makes complete sense to me:


"Carbon dioxide (CO2) is essential for photosynthesis. CO2 in the water comes from fish respiration, or is dissolved from the atmosphere. Just as you need to aerate and circulate water from the lower levels of the aquarium for oxygenation, you need to do the same so that the plants get enough CO2. The amount of dissolved CO2 is not proportional to the amount of dissolved 02. These two factors are independent of each other. Proper aeration and circulation of water will ensure that requirements for both gases are met." Source: So you want to grow plants.... (http://www.aquarticles.com/articles/plants/kumar_plants.html)

I can imagine you are saying, whatever dude... you don't know what you're talking aobut. And I don't blame you... I wouldn't take advice from a complete newb on plants either... but, it sounds like you need to do some more research.

I wouldn't turn off the aeration at all... and if I did... it would be at night when the co2 is off.

[Lady Hobbs]

Please make sure your CO2 is not near the filter uptake or a bubbler as well. I had mine to near one of those and it filled the tank with CO2. Cost me 14 fish in the time frame of 5 hours.

[SpyderSpy6]

I have my CO2 connected to the outflow of my filter. It sits between my filter and my UV Sterilizer. I have heard both sides of whether or not to keep a bubbler on. I just want my plants to thrive without harming my fish.

My airstone sits in the middle of my tank on the back glass.

My LFS said that if I tilt the filter head upward, it will create a ripple in the water which is all I need to oxygenate the water. Is this true? He said if the top of the water is like glass (which mine is without the airstone) then there is no oxygen displacing into the water. I have a spray bar that I can angle upward, and I'm going to try that. Also, I have a surface skimmer, but it keeps the water very smooth.

[RainMan]

If I understand your LFS correctly.... That's exactly how I have mine setup (Sort of)... I also have my air stone positioned so the filtered water will distribute the bubbles across the surface of the water... which in my theory breaks up surface tension even more.

[RainMan]

In short... the more surface agitation the greater the o2 absorption will be. Of course, on the other end... you increase co2 from being released.

[SpyderSpy6]

Is the amount of CO2 lost anything to worried about?

If the surface is agitated enough, do I even need to bubbler, except for at night?

If my pH stays low on it's own, does that mean there is sufficient CO2 in the water?

Thanks for all the help, these are just some of the last questions I had. I am going to try and turn my airstone off for a little while to see what happens. Thanks again everyone!

[RainMan]

You know... the one thing that sucks about this is... the more o2 you are able to increase the less co2 you will have. You can't have both. :(

It's a search to find that fine line where you get a compromise of both worlds.

Unofortunately surface agitation causes 2 things to happen... o2 absorbtion and co2 release.

I think I will stay away from co2 in the future. it's confusing stuff. LOL Good luck... hopefully someone else will add some more insite.

[gm72]

and remember, more co2 doesn't mean less o2 in the water...

Good point. co2 and o2 are independent of one another.

Sounds to me like too much co2 is being injected into the tank. By running the bubbler and co2 at the same time I believe you would be negating the effects of the co2.

Better to dial down the co2 and keep the schedule of co2 when the lights are on, bubbler when the lights are off.

[duce]

i know a discus breeder who uses a protein skimmer to airate his tank . hes just had a new fry of dicus so it must work....

[gm72]

Is the amount of CO2 lost anything to worried about?
No real worry, per se, just know that it is being lost.

If the surface is agitated enough, do I even need to bubbler, except for at night?
No bubbler needed except at night in this case, you got it!

If my pH stays low on it's own, does that mean there is sufficient CO2 in the water?
Not 100% sure about this, but I do know that pH can help determine CO2 concentrations. We'll need a plant guru to come along for this one.

Thanks for all the help, these are just some of the last questions I had. I am going to try and turn my airstone off for a little while to see what happens. Thanks again everyone!

Glad you are getting the information you need!