Co2 injection in large tanks

Zygorf72

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Hi all

I'm running a 530 liter planted tank. I'm injecting co2 into the tank, but have trouble with injecting at a sufficiently high rate. I have a heavily planted setup, so it needs quite a lot of co2. To make matters worse i have close to liquid rock in my tap water, which as far as i understand increases the need for co2 injection even further. I'm running an Aqua Medic 1000 reactor, where the large bioballs it comes with, have been substituted for ceramic rings. I substituted the media, in order to increase turbulence in the chamber, in the hope of increasing the absorption rate of co. The reactor is driven by a large cannister filter - flowrate of 1250 liter/hour. I used to run the reactor on the outflow of the filter, but had trouble with it causing a significant reduction in the flowrate of the canister. I've since changed it to be correctly mounted on the intake of the filter, this however has lead to another problem. The canister sucks in co2 from the reactor, into the canister itself, leading to it "burping" out co2 at regular intervals into the aquarium, through the outtake. Worst case it completely stops the flow, so that i have to re-prime the filter.

My question is this. For those of you who run similar or bigger co2 injected and heavily planted tanks - what setup for injection do you use and have you experienced something similar problems? I'm a bit at my wits end on how to solve this. I'm wondering whether the Aqua Medic simply isn't able to inject enough, no matter what i do. According to Aqua Medic it is rated for up to 1200l tanks. So judging by their rating, it should have more than enough capacity.

Thanks
Nicklas
 

soggybongo

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have you tried a closed loop mate. i.e something like an Eheim 1048. you could either tap into your current filter or have a separate inflow. on the outflow of the eheim 1048 pump could go into the aqua medic 1000 reactor.
 

Zeus.

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Hi Nicklas and welcome to the forum :D

Kezzab has linked my 500l tank above which should contain many of the answers

I'm injecting co2 into the tank, but have trouble with injecting at a sufficiently high rate. I have a heavily planted setup, so it needs quite a lot of co2.

Mine has an insane BPS injection rate and 6.5Kg last a month tops.

I'm running an Aqua Medic 1000 reactor

Not used that myself but I think thats what Green Aqua use on their amazing big tanks so I sure its up to the job its just a case of getting it setup right. Have read about many folk using them without an issue once setup correct

The reactor is driven by a large cannister filter - flowrate of 1250 liter/hour.

Wouldnt call that a large canister and the flow rate is a tad on the low side IMO my FX6 has about of 3000LPH

I used to run the reactor on the outflow of the filter,

:thumbup: - reactor gets filtered water on is under increased internal pressure

I've since changed it to be correctly mounted on the intake of the filter

:thumbdown: reactor gets unfiltered water on is under reduced internal pressure. Increasing the internal pressure increases the CO2 uptake, @foxfish had great success with his reactor with a high working pressure

"burping" out co2 at regular intervals into the aquarium

been there done that with pre inline atomisers :rolleyes: every canister is different and they can only handle a certain injection rate then they burp dependant on design OFC.

Some more details of your 'ALL' hardware and setup will help us to guide you to options which should help resolve your problem ;)
 

Oldguy

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close to liquid rock in my tap water
Have you considered reducing total hardness by cutting your tap water with RO or rainwater which is free. Also why not run CO2 for a longer period but at a slower rate. As posted above, @foxfish designs and makes high pressure CO2 reactors and has posted his designs on the forum, but I know not where. Could be worth a pm.
 

Zeus.

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I was informed that having hard water will require more CO2 for given [CO2] so will use lots of CO2.
But then I think I was informed by @ceg4048 and/or @dw1305 and others as well that the hardness of the water has nothing to do with the amount of CO2 used for given [CO2]. Yes very soft water or 100% RO water can be tricky with CO2 injection
 

Edvet

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Hardness won''t influence the amount of CO2 disolved, it will influence the pH drop for a given amount of CO2.
For a large tank i advice a DIY reactor, a large one or a double setup. Getting good flow is another problem,
Alternatively low dose 24/7 CO2 can work too ( with less light).
 

dw1305

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Hi all,
hardness of the water has nothing to do with the amount of CO2 used for given [CO2]
Hardness won''t influence the amount of CO2 disolved, it will influence the pH drop for a given amount of CO2.
I think it was Clive who told us originally, but you are right the amount of Dissolved Inorganic Carbon (TIC or DIC) is set by the concentration of CO2 in the atmosphere.

co2_hco3.png


When you add pressurised CO2 you have added H2CO3 and the pH falls, how far it falls is dependent on the CO3 reserve ("buffering").

cheers Darrel
 

Zygorf72

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have you tried a closed loop mate. i.e something like an Eheim 1048. you could either tap into your current filter or have a separate inflow. on the outflow of the eheim 1048 pump could go into the aqua medic 1000 reactor.

I used to run an Eheim 2075 canister, with the Aqua Medic 1000 reactor on the outflow. That reduced the flowrate of the canister significantly. I've later changed to Oase Biomaster 600. The picture is the same here. Would an Eheim 1048 be less prone to lose efficiency?

New edit from me: I've since learned that the reduction of flow rate, seems unfair to blame on either of the two filters. It was due to the choice of filter material in the reactor. Both canisters are very nice. I really love the Biomaster 600. It has a better flowrate than the equally rated Eheim 2075. It also enables you to remove the heater from your tank, a feature for which you have to pay dearly for in the Eheim line-up of canisters.
 
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Zygorf72

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Hi Nicklas and welcome to the forum :D

Thanks and thanks so much for you in depth response :)

NIce to hear, that It's unlikely that the reactor-model is an issue. With regard to flowrate, I'm actually running several filters on the tank simultaneously. In total I'm running two Oase Biomaster 600 with integrated heaters (2 x 1200 l/h), one Eheim Skim350 (love this skimmer by the way) and one Tunze NanoStream 6015 circulation pump 1800 l/h. One of the Biomasters is connected to the Aqua Medic 1000 reactor on the inflow-side.

With regard to connecting the reactor to the outflow, my experience is that it reduces the flow-rate dramatically - a rough guess would be around 75% reduction. The idea of mounting it on the outflow side, was for me to have the water filtered, prior to reactor in order to increase the periods between cleaning the reactor. I hadn't thought about the point concerning pressure. That really makes sense though. I still feel the dramatic reduction in flowrate of the filter is an issue. Are there pumps that are less sensitive to a reactor being mounted on the outflow (barring the FX6, which I'm not that inclined to get due to its massive size).

You also requested a liste of all the hardware - It's already listed above :)
 

Zygorf72

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Have you considered reducing total hardness by cutting your tap water with RO or rainwater which is free. Also why not run CO2 for a longer period but at a slower rate. As posted above, @foxfish designs and makes high pressure CO2 reactors and has posted his designs on the forum, but I know not where. Could be worth a pm.

I'm using Estimative Index and thus change 50% water every week. Accumulating that much rainwater and using it for water change, would be a serious hassle for me (I live in an apartment building). I do run co2 3 hours prior to lights-on already. I'll definitely have a look at high pressure reactors - if nothing else to understand more about the impact of pressure in the reactor that Zeus also pointed out.
 

Ady34

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If running multiple filters you could run multiple reactors with smaller injection rate to each which will reduce the ‘burping’ allow better dissolving and also likely improve co2 distribution via different filter outflows.
I understand you may not want to do this due to the flow loss but it would help with your issue of not getting enough co2 into the tank. Distribution could then be addressed with the circulation pumps?

Cheerio
Ady
 

Zygorf72

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Hi all,I think it was Clive who told us originally, but you are right the amount of Dissolved Inorganic Carbon (TIC or DIC) is set by the concentration of CO2 in the atmosphere.
Thanks for the information. Nice to know. That high levels of hardness, increases the needed level of co2 injection is apparently another case of aquarium myths i guess.
 

Zygorf72

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If running multiple filters you could run multiple reactors with smaller injection rate to each which will reduce the ‘burping’ allow better dissolving and also likely improve co2 distribution via different filter outflows.
I understand you may not want to do this due to the flow loss but it would help with your issue of not getting enough co2 into the tank. Distribution could then be addressed with the circulation pumps?

I guess so. I would rather do a setup with the reactor attached to a circulation pump that is less prone to lose circulation efficiency - if that exists. The flowrate of the canisters are reduces so much, that I'm concerned that it impacts the efficiency of the filtration inside the filter as well as the integrated heater.
 

Zygorf72

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I wonder whether the change to using ceramic rings in the reactor, rather than the original large bio balls was a bad idea. The ceramic rings seem to trap small co2 bubbles that gradually work their way to the bottom of the reactor and into the outflow of the reactor. I'll try switching back to the bio balls some time next week and see whether that makes a difference.
 

Ady34

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I wonder whether the change to using ceramic rings in the reactor, rather than the original large bio balls was a bad idea. The ceramic rings seem to trap small co2 bubbles that gradually work their way to the bottom of the reactor and into the outflow of the reactor. I'll try switching back to the bio balls some time next week and see whether that makes a difference.

I ended up with a layer of shower puffs and all sorts in my reactor to try to keep the co2 in the reactor......I could never get it to work properly which is why I tolerate the mist from inline diffusers now, at least those bubbles in the tank are tiny and useful.

BAB735D4-6EE7-4484-8144-00A8653145B9.jpeg
 
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Zygorf72

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I ended up with a layer of shower puffs and all sorts in my reactor to try to keep the co2 in the reactor......I could never get it to work properly which is why I tolerate the mist from inline diffusers now, at least those bubbles in the tank are tiny and useful.

View attachment 121869
I see that your'e running the Aqua Medic 1000 as well. Is your tank size comparable to my tank? (I'm considering whether a bigger reactor (APS EF2) would be the solution for me…). Zeus mentioned that Green Aqua use Aqua Medic reactors. They do use it, however when looking into their videos, I saw in the description for their 650 l aquarium, that they actually run a custom reactor on that. It might be that they felt that the Aqua Medic was insufficient for that tank size.
 

Ady34

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That ran on only a 180l tank and due to my injection rate i always suffered burping and bypass. I guess the main benefit asides the lack of in tank bubbles is that you can get a truer co2 reading in your tank via the drop checker as it isn’t effected directly by the co2 mist.
To be honest I think you will need a bigger reactor if you want to stick with this method. That should allow better flow and the gas to dissolve fully but I am far from experienced with reactors. As I said I couldn’t get away with the am1000 on my 180l tank.
 

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