# Co2 injection in large tanks



## Zygorf72 (15 Feb 2019)

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 (16 Feb 2019)

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.


----------



## Kezzab (16 Feb 2019)

Hi, good discussion of this issue here: https://www.ukaps.org/forum/threads/olympus-is-calling.43046/


----------



## Zeus. (16 Feb 2019)

Hi Nicklas and welcome to the forum 

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



Zygorf72 said:


> 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.



Zygorf72 said:


> 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



Zygorf72 said:


> 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



Zygorf72 said:


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



 - reactor gets filtered water on is under increased internal pressure



Zygorf72 said:


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



 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



Zygorf72 said:


> "burping" out co2 at regular intervals into the aquarium



been there done that with pre inline atomisers  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 (16 Feb 2019)

Zygorf72 said:


> 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. (16 Feb 2019)

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 (16 Feb 2019)

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 (16 Feb 2019)

Hi all,





Zeus. said:


> hardness of the water has nothing to do with the amount of CO2 used for given [CO2]





Edvet said:


> 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. 




 

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 (16 Feb 2019)

soggybongo said:


> 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.


----------



## Zygorf72 (16 Feb 2019)

Kezzab said:


> Hi, good discussion of this issue here: https://www.ukaps.org/forum/threads/olympus-is-calling.43046/


Thanks. I'll definitely have a look at that.


----------



## Zygorf72 (16 Feb 2019)

Zeus. said:


> Hi Nicklas and welcome to the forum



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 (16 Feb 2019)

Oldguy said:


> 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 (16 Feb 2019)

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 (16 Feb 2019)

dw1305 said:


> 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 (16 Feb 2019)

Ady34 said:


> 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 (16 Feb 2019)

Kezzab said:


> Hi, good discussion of this issue here: https://www.ukaps.org/forum/threads/olympus-is-calling.43046/


Thanks. Will have a look.


----------



## Zygorf72 (16 Feb 2019)

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 (16 Feb 2019)

Zygorf72 said:


> 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.


----------



## Zygorf72 (16 Feb 2019)

Ady34 said:


> 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 (16 Feb 2019)

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.


----------



## Zeus. (16 Feb 2019)

Zygorf72 said:


> if nothing else to understand more about the impact of pressure in the reactor that Zeus also pointed out.



I run my reactors at a low pressure compared to what foxfish did esp with having a bypass fitted to keep flow optimal in the tank, the flow I can have in the reactors can be very low with the bypass fully open and yet i still get fast 1.5pH drops but at a high CO2 injection rate





I have recently fitted Maxspect Gyres for tank flow/turnover is well taken care off. I have tried running the reactors at higher pressures/flow rates but they become too noisy and no net gain in the test I have done so far.

Filter flow rate isnt that important IMO is it doesnt increase the biological filtration rate it will pull more water though so will help remove more particles so mechanical filtration will be faster, but if you can keep the turnover higher in the tank by other means the particles will remain suspended in the water longer and the mechanical filtration will happen. As @ceg4048 points out to us the largest biological filters in our planted tanks are the plants esp the plant roots. Flow/Tankturnover is 'KING' in the planted tank for which we mainly use filter output to get, the advise is X10 output per liter of tank water, but we can also use powerheads etc to get the flow/output then the filter output is less a critical factor. We have also discussed the tanks at Green Aqua on the forums - stunning tanks Very high light yet relatively low flow/turnover rates, I have been to Green Aqua and they are stunning with relatively low flow rates


----------



## Zygorf72 (17 Feb 2019)

Zeus. said:


> I run my reactors at a low pressure compared to what foxfish did esp with having a bypass fitted to keep flow optimal in the tank, the flow I can have in the reactors can be very low with the bypass fully open and yet i still get fast 1.5pH drops but at a high CO2 injection rate



Out of curiosity - what sort filter material do you use in the APS reactors? I didn´t seem to be described in the thread concerning your tank. At least I couldn´t find it.


----------



## Zeus. (17 Feb 2019)

Bioballs some details-
Co2 reactors setup and detritus build up

Plus working on 
CO2 APS EF2 reactor with internal Venturi fitted - testing ATM

But have found little difference in pH drop speed or stable [CO2] if I use the boiballs or not  but work in progress on and off (Off ATM)


----------



## Zygorf72 (17 Feb 2019)

Zeus. said:


> Bioballs some details-
> Co2 reactors setup and detritus build up
> 
> Plus working on
> ...



Interesting idea with the Venturi - I'll definitely be following that thread.

The Aqua Medic runs a bit differently than your setup, in the sense that it doesn't use a diffuser before the reactor. It simply bubbles co2 directly into the reactor chamber, without diffusing it. I think my approach for now will be this: I'll try substituting the ceramic rings for large bio balls (the ones that the reactor originally came with). This should hopefully eliminate the problem of smaller bubbles moving down the column of bio rings in the reactor and entering the outflow of the reactor. The question is, whether it will reduce the absorption rate of the reactor. It seems already to be running at the edge of its capacity. If it isn't capable of dissolving co2 to the required level, i guess the next thing would be to introduce a larger reactor chamber. The APS EF2's seem like a nice and fairly priced solution. Would like to get a see-through model though. I find it nice being able to see into the chamber, allowing one to actually see the waterflow and dynamics of the co2-gas within the chamber.

Although I do see the benefits of having the reactor on the outflow-side of the filter, I would like to avoid impairing the flow-rate. The Oase Biomaster really doesn't handle that well (otherwise it is the canister I've tried, I currently like the best). I dont mind cleaning the reactor chamber once in a while, if that is the main drawback. If and how much impact it will have on absorption rate, having it on the low-pressure side of the filter - I don't know. I'm currently running my canister on reduced flow, to avoid too much CO2 to enter it. It doesn't seem to impact the absorption rate significantly. I sounds like you have similar observations, using low flow in you reactor. Il try it out and see where it gets me. If that doesn't solve it, I guess I could look into closed loops or separate circulation pumps. I would like to avoid that starting off, since it will mean further investments and potentially more pumps humming in my living room.

With regard to flow rate - there seems to be a lot of different opinions on what the target turnover rate should be. I'm aiming for 6 times pr hour currently, which I've seen some people advocate. The reason for this, is that i have Angelfish in my tank - and they don't like to strong flow. The current flow-level of the tank is ok for them. 10x flow would almost certainly leave them being blown around the aquarium


----------



## Zygorf72 (18 Feb 2019)

FYI i took the liberty of asking Green Aqua. They have set it up on 800 liter installations, so in their experience it should be able to drive a tank my size (530 liters). They do point out, that one needs good circulation of the water from the reactor, in order to ensure proper disperson of the co2 in the aquarium water column.


----------



## Zeus. (18 Feb 2019)

Zygorf72 said:


> i took the liberty of asking Green Aqua







Zygorf72 said:


> They do point out, that one needs good circulation of the water from the reactor, in order to ensure proper disperson of the co2 in the aquarium water column



 which I would agree with in the sense good flow/turnover in the tank. As IME I can have low flow though my reactors and yet I can still get a 1.5pH drop in 30mins, so i cant see why high flow though the reactors is a requirement. Yes I do have a unique CO2 injection method with pH controler and PLC which I use to its full advantage and have different CO2 injection rates from CO2 on till max lights till CO2 off but I do have a fast pH drop then a steady pH from lights on till CO2 off. But most only have single steady CO2 injection which works also.

I do have the bypass on my reactors but most folk dont have. Increase working pressure in the reactor will/should help but not a requirement IMO/IME. most of Green Aquas reactors are high in the cabinet ( Had I good look when I visited) mine are on the base of my cabinet so maybe that helps too for me with lower flow but if higher better flow though the reactor is needed . High flow though my reactors makes them very noisy and I end up with CO2 bubbles in tank so its a no no for me.

Every ones experience/opinion is different with CO2 injection and I have yet to find anyone who has a decent set of results/test/experiments to what works best and reasons to back it up, which isnt surprising as there are so many variables in our tanks


----------



## Zygorf72 (18 Feb 2019)

Zygorf72 said:


> FYI i took the liberty of asking Green Aqua. They have set it up on 800 liter installations, so in their experience it should be able to drive a tank my size (530 liters). They do point out, that one needs good circulation of the water from the reactor, in order to ensure proper disperson of the co2 in the aquarium water column.



A little additional info from Green Aqua. They recommend a flowrate of around 900 l/h in the Aqua Medic reactor in order to achieve the best efficiency. They also recommend having the reactor on the outflow side of the driving pump or filter. Didn't say why. Just thought I'd add this to the discussion, so that others may benefit from Green Aquas response also


----------



## Zygorf72 (18 Feb 2019)

Zeus. said:


> ...and I have yet to find anyone who has a decent set of results/test/experiments to what works best and reasons to back it up, which isnt surprising as there are so many variables in our tanks



Doesn't that apply to just about anything concerning planted aquariums?


----------



## Zygorf72 (23 Feb 2019)

Ok. So I swapped the ceramic rings in the reactor out for the original bioballs for the reactor. While I was at it, I switched the tubing out, so that the reactor now is mounted after the filter, rather than before. Switching back to the bioballs made a massive difference. The flow of the filter was radically improved - also even though the reactor was mounted after the filter, rather than before. I would guess that the reactor, after switching back to the bioballs, reduces the flowrate of 10-20%, which to me is acceptable. The absorbtion rate of the reactor is all of a sudden massively improved also. It seems to me that this can be attributed to either of two factors. Sufficient flow (around 1000 l/hour) and/or higher pressure in the reactor, due to it being mounted after the filter, rather than before (at 1200 l/hour the filter actually creates a siginificant underpressure on the intake side). At a flowrate of 1000 l/h I had trouble, that the CO2 from outlet of the reactor was sucked directly into the outflow, rather than stay in the reactor. By standard the CO2 is bubbled out by a tube near the outlet of the reactor. Removing the tube, so that the CO2 bubbles out in the top of the reactor instead, completely remedied this issue.

I originaly swapped out the bioballs due to people on forums advocating that Eheim Mix (rough mechanical filter material) or ceramic rings would improve absorbtion rates. I've tried both and my conclusions are these. At flowrates of 1000 l/h Eheim Mix is inefficient, as the waterjet of the filter, simply sprays right through the material in the reactor. Ceramic media on the contrary reduces and restricts the waterflow so much, that the reactor (and the filter) becomes inefficient. It also has the negative effect of creating smaller co2 bubbles that reach the output side of the reactor, either escaping in to the filter or out in the aquarium itself - depending on whether the reactor is mounted before or after the filter.

To sum it up - here's my advice on the Aqua Medic 1000 reactor, based on my own observations:
- The Aqua Medic 1000 reactor is more than capable of supplying a 530 liter planted tank, when setup right.
- Mount the reactor after your filter or pump - it seems to increase the absorbtion efficiency of the reactor due the increased pressure in the reactor.
- Make sure that you have a flow around 1000 l/h in the reactor. This rate of flow seems to make it highly efficient.
- If you have trouble that the CO2 is sucked out of the bottom of the reactor, rather than bubble up into the reactor itself - remove the tubing inside the reactor, so that the CO2 bubbles out in the top of the reactor, rather than the bottom. This remedies the problem and does not seem to impact the efficiency of the reactor in any significant way.
- Do not swap the bioballs in the reactor for other media types. The bioballs are very efficient, when the reactor is set up right.
- The only flipside of the bioballs, is that it makes the reactor have the sound of running water. When it is behind closed doors in my aquarium cabinet, It is not loud enough to be bothersome to me. It might be to others though. Personal taste i guess.

I hope this can be useful for other owners of the Aqua Medic 1000 reactor.

Cheers


----------



## Daveslaney (27 Feb 2019)

Maybe one of these could make a good co2 reactor?
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/370088136785


----------



## Daveslaney (27 Feb 2019)

Or a transparent filter booster?
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/173754769058


----------



## Costa (27 Feb 2019)

Zygorf72 said:


> To sum it up - here's my advice on the Aqua Medic 1000 reactor, based on my own observations:
> - The Aqua Medic 1000 reactor is more than capable of supplying a 530 liter planted tank, when setup right.
> - Mount the reactor after your filter or pump - it seems to increase the absorbtion efficiency of the reactor due the increased pressure in the reactor.
> - Make sure that you have a flow around 1000 l/h in the reactor. This rate of flow seems to make it highly efficient.
> ...



Thank you so much for this, very useful.

The only other problem that I see with this reactor is the tube size. For a 200-400gal tank, 12/16 tube is a very small diameter, which means that a bypass must be installed off the main pump/canister tubing, and that makes hitting the sweet spot of 1000lph even harder.


----------



## Daveslaney (27 Feb 2019)

Yes this is the problem with regards to flow. But as most off the shelf reactors seem to be in 12/16 pipework size. Maybe the smaller pipe is for increased pressure in the reactor to aid co2 desolving rates?
So even thought the flowrate/ turnover through the reactor is less you will actually get more co2 dissolved into the water due to the higher pressure/ better desolving rate?


----------



## Zygorf72 (27 Feb 2019)

Costa said:


> Thank you so much for this, very useful.
> 
> The only other problem that I see with this reactor is the tube size. For a 200-400gal tank, 12/16 tube is a very small diameter, which means that a bypass must be installed off the main pump/canister tubing, and that makes hitting the sweet spot of 1000lph even harder.


You're welcome 

Funny. My Aqua Medic 1000 reactor actually supports 16/22 hoses. It used to have an adapter that supported both 12/16 and 16/22. I sawed off the section with 12/16 barbs, and drilled the entry hole bigger. They must have changed the design, since I bought mine (it's really old 

I would agree that 12/16 is a a little small, when going for a flowrate of 1000 l/h....


----------



## Zygorf72 (27 Feb 2019)

Daveslaney said:


> Or a transparent filter booster?
> https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/173754769058


This looks like the one Zeus uses in his setup described further up this thread. I contacted pond solutions, who are the sellers of this prefilter. It's not actually transparent irl. The picture is to examplify the filter material inside. The actual model is non transparent, like the ones on Zeus pictures.

Sendt fra min Nokia 7 plus med Tapatalk


----------

