Trying to get the CO2 level stable throughout the entire tank

[GillesF]

Hi guys

My plants aren't doing great except some species (Java moss looks excellent, crypto Wendtii is fine too), especially my HC doesn't want to grow. It did have some stems growing upwards. I trimmed these and adjusted my CO2 level. However, I noticed that one side of my tank has more CO2 (yellow DC) compared to the other (lime green DC). I know this has to do with the water current but how do I get this even as much as possible?

This is a picture of my "water current setup":

View attachment 1973

The filter is an Eheim Ecco Pro 200 (600l/h). Extra powerhead is 250l/h. The aquarium is 60x40x40cm and about 90l (23 gallon). The reactor is a glass one that creates tiny bubbles, creating a mist throughout the tank.

Should I buy a stronger powerhead, e.g. a Koralia Nano (900l/h)? Or would that be too much?

Thanks,
Gilles

 

[pepetj]

I don't think you need to get a powerful pump but to upgrade to needle wheel (not hard as DIY). I use quite small powerheads (or small internal filters) in most of my tanks. I can't tell if my CO2 is evenly distributed but I have not found significant differences when measuring samples from different parts of the same tank with the Hach CO2 test kit.

Pepetj
Santo Domingo

 

[Biollante]

Reactor?

Hi Gilles,

Are you using a glass CO2 diffuser with a reactor?

The simple answer may be to add another power-head.

{Warning: This is for reasons I cannot fathom, controversial here.}

• Difference in CO2 levels through-out an aquarium are common.
• The better answer in my ever-humble-potted-plant opinion is first to get more of the CO2 in solution.

Biollante

 

[Hallen]

Are you using a glass diffusor or a real reactor?

I have a slightly smaller tank (60x30x30cm) and I use a eheim 2013 which is 440l/h with a spraybar, together with a AM1000 reactor which I modified so it isn't that much of a bottle neck anymore. Alongside with a small 50l/h pump to get some more current on the substrate so the nutrients distribute better. All in all my Co2 ratings differ only a little where I measure them. Exception is my dense Microsorum bush, there the ratings are a bit lower since the current stops there at the intake of my filter. (Using a 4dkh Co2 checker btw)

I dont think you need more current per se, you just might want to change the way it's flowing first to test things out. A nice and easy way to check where your current is going is by using some 'vloeibaar filtermedium' from EasyLife. This will form a harmless cloud in the tank. If you pour it right beside the filter outflow you can see exactly where and how fast the current is flowing.

Also lime green and slightly yellow are both pretty decent/good Co2 ratings. I'd search for the solution for your elsewhere, i.e substrate, nutrients, current in general (are the nutrients reaching the plants), etc.

 

[GillesF]

This is the reactor I'm using: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250349595543&ssPageName=STRK:MEWNX:IT . It is connect to a pressurized CO2 system. I have already thought about using an inline reactor but I have had so much trouble with this tank that I simply don't want to take the risk anymore. The (super cheap Chinese) powerhead I use now works fine but the problem is that I cannot direct the water current. It might work if I use a bent plastic tube and put it on the outlet.

My problems (slow or no growth, some stunted P. Stellata, some bear algae a few weeks ago, ...) indicate insufficent CO2, so I'm pretty sure that's the problem.

Substrate: Colombo Florabase Black

Nutritiens:


Monday: 50% WC + 10ppm NO3/1ppm PO4/2,5ml micro (Easy-Life Profito)
Tuesday: 2,5ml micro + 1ppm Ferro
Wednesday: 10ppm NO3/1ppm PO4
Thursday: 5ml micro + 1ppm Ferro
Friday: 10ppm NO3/1ppm PO4
Saturday: 5ml micro + 1ppm Ferro
Sunday: relax and enjoy!

I have boosted NO3 and PO4 a little this week.
Not sure about the Ph, KH and GH, haven't tested it for a while, but it should be: 6,5/4/10
Lighting: 1x 24w T5 HO, 8h

I will try the EasyLife trick, sounds like a good idea!

 

[dutchy]

some bear algae

Some bear algae? not grizzly I hope

Stunted Stellata is typically a CO2 problem. As I'm always fiddling around with my tank and experimenting, I reduced the flow with a 1000 gph. Two days later some Stellata's started to stunt.

What I think is a good flow setup, is letting two sources, left and right, (powerheads, filters etc.) flow to each other just under surface level. This creates a heavy downward flow in the middle of the tank which creates an undertow back to the source.

A 24 x 12 x 12 tank should be very easy to do.

regards,
dutchy

 

[Hallen]

Your tank is very similar to mine in terms of tech and substrate. Judging by your dosing regime I assume you have enough nutrients. Since you ruled most of the other possibilities I have to revoke my statement and support your first idea, the big bad old Co2

As Dutchy also said, stunting is a typical Co2 problem. I also like his idea for creating an undertow quite alot, definatly something I'd try out in a new tank.

I'd play around with some VFM so see how the current flow is and based and then based on that make some changes to increase flow, and thus spreading of Co2.

 

[GillesF]

I have a second reactor by the way, maybe I can split up my co2 to two reacors? It's funny actually, when I started this tank, I didn't want any equipment visible in the tank. Now I have more equipment then in my previous aquarium!

 

[hbosman]

"What I think is a good flow setup, is letting two sources, left and right, (powerheads, filters etc.) flow to each other just under surface level. This creates a heavy downward flow in the middle of the tank which creates an undertow back to the source."

Very interesting idea! I have to try this tonight. I use the mist method so it should be very obvious how flow is directed.

 

[GillesF]

I tried the VFM trick and the majority of the liquid stayed in the front right corner (in front of the powerhead). It takes some time to fill the front left corner but eventually it gets there. I'll try out different positions for my powerhead and reactor. Maybe I could put the reactor in front of the filter outlet and have the powerhead flow to the outlet?

 

[pepetj]

Dutchy... Is this what you mean by left and right CO2 injection flow facing each other just below water surface?

If possible I would like to see (graphically) what you mean by creating a "heavy downward flow in the middle of the tank which creates an undertow back to the source".

May seem like a stupid question but I don't get the idea as clearly as I would like to.

Pepetj
Santo Domingo

 

[Gerryd]

Peptj,

I think the flow from each side as it is close to the surface (just below) will meet in the middle and push each other downwards. This will then hit the substrate and bounce off the substrate.

If it flow back to the sides, I think you will get a nice motion of flow.

However, I am not sure that is what he meant.

 

[GillesF]

I will try that method today and report the results.

GillesF

 

[dutchy]

I think the flow from each side as it is close to the surface (just below) will meet in the middle and push each other downwards. This will then hit the substrate and bounce off the substrate.

That's what I meant, only I have my outflows in the middle of the tank, seen from the top. This will create two vertically orientated circular flows from top to bottom, forcing CO2 bubbles right to the substrate.

 

[hbosman]

Last night, I changed my CO2 dispersion similar to Dutchy’s method. My canister filter output is in the upper - back – left, aimed at the upper - back - middle. The powerhead inline diffuser combo is in the upper - back – right aimed at the upper - back – middle. The flow from both meets in the middle, deflects down to the gravel, flows through the middle planting, hits the front glass and disperses left and right. This creates a highly concentrated mist everywhere. It isn’t very attractive but very effective, I think.

I will keep it this way and see how it effects the plant growth. I have Bolbitus, Rotala Macandra green and red, two varieties of Cryptocoryne Wendtii, Ludwigia and staurogyne repens 049. Everything except the Rotala Macandra red is growing well so, I have a test plant to observe.

Thanks Dutchy for the idea.

 

[GillesF]

And where do you have your reactor?

I noticed today that the DC is now yellow in the left corner too. Maybe I should leave it as is?

 

[hbosman]

I'm using a powerhead with an inline co2 diffuser.

http://cgi.ebay.com/Aquarium-CO2-Na...801?pt=LH_DefaultDomain_0&hash=item53e4c2e291

 

[GillesF]

I prefer not to have another external filter/powerhead. I did find this on Ebay: http://cgi.ebay.com/Aquarium-Co2-At...431?pt=LH_DefaultDomain_0&hash=item25574383ef

Any good?

*edit* Nvm, the one by Hbosman is works the same lol

 

[Gilles]

@Hallen, i am very interested in this. what did you do? Pics?

together with a AM1000 reactor which I modified so it isn't that much of a bottle neck anymore

@hbosman, does this work for you? I mean this method creates a huge mist in the tank? You don't use a co2 reactor anymore?

 

[GillesF]

What bothers me most about those inline diffusers is the risk of water leaks. I live in a roof appartment with a wooden floor and really don't want 20 gallons of water all over it lol ...