# co2 in a low light tank



## plantnoob (31 Dec 2014)

im considering having another try with co2 , not 100%  decided . its mainly going to be decided be wether or not i can find a cheap local supplier / refiller of bottles .  ive also got a lot of questions that will affect the decision.

1) what sort of benefits could i expect if implemented properly withthe tank being low light . ( low being 2x40w t8over a 4ft 240L)

2 )  is co2 easier to manage at lower light levels. last time around using t5ho i was forever fighting algae.

3) flow/distribution . this is the tricky 1 . my rtnk is a fluval roma 240and the foltration is set up using holes and standpipes drilled at 1 end of the tank . at the moment the outflow from filter gos from right to left , with a fluval u4 at opposite end but flowing in the same direction, towards the right hand end glass.budget  wont allow me to buy extra cannistef filters and do full length spraybars on back wall. what about move the u4 onto the right hand end glass (i could hide this with plants) have both the fluval 306 and the u4 flowing from right to left and supplement this with a powerhead also flowing from right to left , with co2 atomiser at the substrate levelthe opposite end of the tank so hopefully the bubbles get forced down and along the substrate?


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## Edvet (31 Dec 2014)

Have a look at our low tech section and the famous tanks of Alastair and Big Tom in the featured journals. These go to show you can do great things in low tech/low light tanks without  CO2. CO2 is needed in high light tanks but when used in low light tanks it can work, but only if you can keep it very stable. It's like a drug to plants and once used to higher amounts they don't like to go "cold Turkey" or inconsistent amounts. There are some tanks who do great on Bio co2 in the journals too.


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## plantnoob (31 Dec 2014)

at the moment im just weiging upmthe pros and cons to decide if the return is wortj the investment for my current setup .


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## Jose (31 Dec 2014)

plantnoob said:


> 1) what sort of benefits could i expect if implemented properly withthe tank being low light . ( low being 2x40w t8over a 4ft 240L)



Hi,
Plants will grow better with CO2 even in low light. Also you could grow more kinds of plants.




plantnoob said:


> 2 ) is co2 easier to manage at lower light levels. last time around using t5ho i was forever fighting algae.



Its much easier with low light. This kind of tank is ideal for me and my lifestyle.




plantnoob said:


> 3) flow/distribution . this is the tricky 1 . my rtnk is a fluval roma 240and the foltration is set up using holes and standpipes drilled at 1 end of the tank . at the moment the outflow from filter gos from right to left , with a fluval u4 at opposite end but flowing in the same direction, towards the right hand end glass.budget wont allow me to buy extra cannistef filters and do full length spraybars on back wall. what about move the u4 onto the right hand end glass (i could hide this with plants) have both the fluval 306 and the u4 flowing from right to left and supplement this with a powerhead also flowing from right to left , with co2 atomiser at the substrate levelthe opposite end of the tank so hopefully the bubbles get forced down and along the substrate?



What you already have will most likely do it for your set up. Just make sure your flows are alll going in the same direction. This way you dont break the flow with one another.

Your diffuser can be in different places depending on the flow.
1) If flow is strong enough then you can put the diffuser on the oposite side to the flows source. If you see bubbles pushed down by the flow then this isa good configuration.

2) If the flow isnt strong enough to get to the other side of the tank and push bubbles around then you can just put it unde the flow´s source output.

You can get a cheap fire extinguisher, regulator and a good atomizer probably for less than 70 pounds but of course it depends where you buy. Also the FE exchange is an important factor to consider.

I would go for an inline atomizer.


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## plantnoob (31 Dec 2014)

1 thing i remember wheni used an inline atomiser was losing most of my bubbles to the surface  .


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## Jose (31 Dec 2014)

It has to be a quality one. An intank atomizer is also a good option.  Atomizers wether inline or intank are better because of the small size of the bubbles. Some say atomizers but they are just standard difusers.

You can use a reactor if you want. Whatever you feel confortable with.


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## plantnoob (31 Dec 2014)

i like the idea of reactors meaning the tank wont have the "7up" look but fro  what i read the mist is more effective for the plants , is that true?


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## Jose (31 Dec 2014)

It is for me. The main thing is that its easier to control and 90% less risk of gassing your fish ime.

I just look at ADA tanks and how good they look ad how they pearl with just some mist in the tank which isnt even well distruted around the tank.
Whilst to acieve the same with a reactor its just so risky that i dont advise it to beginners (not saying you are one).


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## plantnoob (31 Dec 2014)

some real food for thought here.  so far biggest attraction is the increased plant choices


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## Jose (31 Dec 2014)

In the end its all up to you. You can grow almost any plant with CO2 and low light although Im not sure how low is your light. Because there is no easy way of knowing.


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## foxfish (31 Dec 2014)

I guess different folk have different opinions but for me a low light (like your lighting) is the easy way to go if you add C02.
There are just thousands of post on this forum advising low light!

Lots of C02 and not so much light is a great way to go......

I am not sure why Jose suggest it is 90% less likely to gas fish with a reactor though? 

I think generally speaking an anatomiser is a very fine ceramic that requires a high working pressure & a diffuser has a more course ceramic that requires less pressure & slightly larger bubbles.
From my experience, devises that produce an in 'line mist' are very effective but, I don't like the mist effect at all - so for me it is a reactor as first choice.


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## Jose (31 Dec 2014)

foxfish said:


> I am not sure why Jose suggest it is 90% less likely to gas fish with a reactor though?



Its less likely to gass fish with a difuser (sorry for not making myself clear)

With a reactor all the CO2 to be used by plants is dissolved in the water whilst whith an atomizer small bubbles of CO2 in the gas form stick to plants making it more available for plants.


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## pepedopolous (31 Dec 2014)

Whether high light or low light I think CO2 injection needs to be stable.

P


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## plantnoob (31 Dec 2014)

Jose said:


> In the end its all up to you. You can grow almost any plant with CO2 and low light although Im not sure how low is your light. Because there is no easy way of knowing.


 works out at 0.333333 watts per litre of t8 so pretty low


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## plantnoob (31 Dec 2014)

pepedopolous said:


> Whether high light or low light I think CO2 injection needs to be stable.
> 
> P


 of course but the slower pace /lower demands  of lower light must be mkre forgiving when it comes to finding the balance


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## Jose (31 Dec 2014)

plantnoob said:


> of course but the slower pace /lower demands of lower light must be mkre forgiving when it comes to finding the balance


I dont even measure my co2. I just like to see micro CO2 bubbles going to as many places as possible. This is why I love atomizers so much.

Oh and 0 algae at any stage of my tank.

Another trick is to seed your filter with bacteria for the starting phase.


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## pepedopolous (31 Dec 2014)

I don't like the lemonade look but if you can get CO2 so both plants and fish are happy that's 90% of the battle or maybe 99%!

P


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## plantnoob (31 Dec 2014)

torn between reactor for viewing and atomizer for effectiveness. tank is up and running jose . was seeded with mature media and currently houses 2 keyhole cichlids


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## Jose (31 Dec 2014)

pepedopolous said:


> I don't like the lemonade look but if you can get CO2 so both plants and fish are happy that's 90% of the battle or maybe 99%!


Also in my tank I dont get this effect because I inject minimal CO2 but this is a quite low light tank, so I do understand people who dont like it. Also with more light the bubbles become even more aparent.

Reactors for me are just really hard to dial in. It can take you days to get to the desired ppm, and the it takes seconds to go wrong again if you dont have a good needle valve or sometimes just a water change can change CO2 levels for some hours.


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## plantnoob (31 Dec 2014)

Jose said:


> Also in my tank I dont get this effect because I inject minimal CO2 but this is a quite low light tank, so I do understand people who dont like it. Also with more light the bubbles become even more aparent.


any chance of a video showing the extent of ypur bubbles jose?


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## Jose (31 Dec 2014)

Im afraid my tank is a few kms away from me at the moment LOL. Im in Spain for christmas. Hopefully fish wont be dead when i get back after two weeks.

Ill post a link of the tank but unfortunately the filters were turned off for the photoshoot.

http://www.ukaps.org/forum/threads/no-quintaessence.35503/

I know its a small tank but most things can be scaled up.


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## plantnoob (31 Dec 2014)

no worries . quite tricky to shoot from that distance .


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## Jose (31 Dec 2014)

http://www.ukaps.org/forum/threads/5-l-nano-highish-tech.34856/
Here is another tank of mine I got banged at really badly for keeping a gourami in 5 litres Lol.


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## plantnoob (31 Dec 2014)

also i guess that with fine enough mist , if i can keepmit down at substrate level until its traveled the length of the tank , that a fair bit would dissolve by the time its travelled 4 feet too so lemonade effct possibly further reduced?


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## Jose (31 Dec 2014)

plantnoob said:


> also i guess that with fine enough mist , if i can keepmit down at substrate level until its traveled the length of the tank , that a fair bit would dissolve by the time its travelled 4 feet too so lemonade effct possibly further reduced?


Exactly. If the flow is highish at the spot of the diffuser/atomizer then bubbles are very very small and they get dissolved even further as they travel and thats why I can barely see them unless I look very closely.
You shouldnt see anything from your sofa or at 2 feet from the tank. If you do see then bubbles are too big IMO.


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## plantnoob (31 Dec 2014)

well the flow will be coming from a fluval 306 rated i believe at 1150lph , a fluval u4 rated at 1000 lph and an as yet undecided powerhead but probably at least in the 1600lph region all flowing from right to left . should be pretty strong id of thought


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## Jose (31 Dec 2014)

plantnoob said:


> well the flow will be coming from a fluval 306 rated i believe at 1150lph , a fluval u4 rated at 1000 lph and an as yet undecided powerhead but probably at least in the 1600lph region all flowing from right to left . should be pretty strong id of thought


Id think so. Probably too much. Might be enough with only the two filters since its low light. You also ought to have some surface ripple. It prevents many problems.

When I set up one day my discus tank it will be this kind of a tank. Thats if I can someday afford an apartment or something in UK which seems impossible


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## plantnoob (31 Dec 2014)

i think il experement  now by putting the u4 same end as the external and havethem both flowing right to left . ist the possible loss of momentum over 4 feet that concerns me


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## Jose (31 Dec 2014)

Another option could be one of them going righ to left through the back and the other one going left to right through the front. This should create a circular motion if tank is wide enough. If you are going to have lots of tall plants at the back then not the best idea.


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## plantnoob (31 Dec 2014)

yep lots of tall plants at the back , crypts , annubias etc in the midground and a carpet of sagitaria subulata in the foreground . ive just swapped the u4 to be at the same end as the external outlet . at the opposite end of the tank flow is so strong plants are bending over but once its about 3/4 along the way back to source end is slows noticably . although i do have a rather large chunk of bogwood at that end which must be acting like a big buffer stop . that is getting swappedmout for a branchy piece of redmoor soon though .


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## Jose (31 Dec 2014)

It doesnt need to be very strong at the oposite side. Dont worry too much it looks like its just fine.


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## plantnoob (31 Dec 2014)

perhaps its even a bit too strong . there is a stem of L. sesiliflora about 9 inches tall the opposite end to the filters and flow forcing down the glass that end of the tank is so strong its almost laid on the substrate!


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## Jose (31 Dec 2014)

Then try just with one filter. The 10x rule is well overestimated. The main thing is your intuition. Also in the front of the tank there shouldnt be anything in the way of the flow. This is normally the case for most scapes.


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## plantnoob (31 Dec 2014)

what i may do is do away with the u4 , after all it is a big ugly black box with a very narrow jet of flow , and swap it out for a newave 1.6 wavemaker . adjustable from 800 to 1600lph and probably more diffused/spread out flow .


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## Jose (31 Dec 2014)

plantnoob said:


> what i may do is do away with the u4 , after all it is a big ugly black box with a very narrow jet of flow , and swap it out for a newave 1.6 wavemaker . adjustable from 800 to 1600lph and probably more diffused/spread out flow .



Sounds good.


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