Complicated Co2 setup - need help finding the right approach to determing correct Co2

[tim_s]

Hi Everyone,

I am brand new to plants and I have began a setup which already will come with challenges and I am looking to get this fixed.

My Tank
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90 G Display tank
35 G Sump (I removed the wet dry for planted)
Has 2 over-flows

Lights
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I have a 4 bulb T5HO Tek Elite with 2 daytimes, 1 red spectrum I think from coralife? and the last I will have to look up when I get home.

Dosing
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I am currently dosing Seachem Flourish (standard) every water change which is weekly. I am changing 45 G but dosing the whole water volume each time.

Co2
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Currently I have a 20lb cylinder of beverage grade Co2 with the Red Sea Co2 Cylinder Pro Kit w/ Solenoid.

The reactor is right in-front of my return pump which is return water into the display tank under the water line.

To prevent gassing out as little as possible the output from the over flow is being returned under the water line within the sump.

Fish
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I have a small stocking right now,

4 x Bolivian Rams
1 x Kribensis

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My question, according to the PH / KH Co2 Charts being a KH of 4 and pH of 7.6 - My tank already had too much Co2 before adding the pressurized kit. What is the best approach to determine whether my Co2 is being dissolve correctly?

 

[tim_s]

Some more information.

Plants

I have 4 different variants of amazon swords

Water Surface

Outside of the over flows and when the water level drops within the sump the surface is like glass in both the display and sump.

 

[tim_s]

Let me know if I can provide more information.

 

[CorallineAlgae]

You will definitely need a drop checker and 4dKH solution to get a better idea of the actual co2 level in your tank. I use the same KH/pH chart system to get an idea about where to initially set my pH controller for the co2 system. The chart is fairly close but always a off by a tenth of a point or two. Buffers in the water can and do alter the outcome of the actual co2 to KH to pH scale. Errors in testing pH or mostly KH also come into play. Using a drop checker has been the most usable way to monitor co2 for my system.

 

[aqua_chem]

My tank already had too much Co2 before adding the pressurized kit.

What does this mean?

 

[tim_s]

Hi,

Sorry English is not my first language and I know my grammar is far from perfect.

When observing my KH is 4 dKH and my pH is 7.6 on the Co2 Chart I noticed that my readings where within the "Too much Co2" range previous to me adding the Co2 system.

Does this help?

 

[aqua_chem]

The KH/pH/CO2 relationship is flawed at best. It depends on a number of assumptions that are commonly not correct in our tanks, namely that carbonates are the only buffers and that CO2 (carbonic acid) is the only acid, either of which are usually wrong to a degree, but often extremely so as in your case.

Getting a drop check is by far your best option. They can be had for fairly cheap online.

 

[tim_s]

Being that my water is set at 4 dKH and the Red Sea Co2 Pro kit already has one - I will deploy this ASAP

I was concerned that having such a volatile liquid within the water line is just adding another failure point.

 

[aqua_chem]

Make sure you use your own low range pH test kit and not what comes with the kit. The indicator solution we use, bromothymol blue, isn't particular volatile and pretty dilute.

 

[tim_s]

For fresh water I own the API low pH test.

Make sure you use your own low range pH test kit and not what comes with the kit. The indicator solution we use, bromothymol blue, isn't particular volatile and pretty dilute.

If I understand correctly instead of adding the low pH testing regent to the submerged co2 test I should be using the API low pH test which is designed to test pH within 5 ml solution within a test tube.

Am I correct in this assumption or am I miss-reading your comment?

 

[CorallineAlgae]

That's what everybody uses for their drop checkers. Lots of people get Chinese made glass drop checkers that come with junk reagent, if any, and should be tossed. The Red Sea kit comes with the proper reagent. They make great test kits too after all. I have the same Red Sea pro kit you have and the drop checker and drops are both great to use. When the liquid gets old the API low range reagent is a perfect replacement and it's cheaper that the Red Sea liquid. You can use either but it only takes two drops as the DC only uses 1ml of water. The more important thing to me is that the 1ml of water you use be 4dKH water instead of tank water.

 

[jetajockey]

I got a red sea drop checker a few years ago and it still needed 4dkh reference solution. All it came with was a small indicator liquid dropper bottle of bromothymol blue (i.e. low range ph test). Is the newer kit different?

 

[CorallineAlgae]

I got a red sea drop checker a few years ago and it still needed 4dkh reference solution. All it came with was a small indicator liquid dropper bottle of bromothymol blue (i.e. low range ph test). Is the newer kit different?

It's still the same. 4dKH reference solution isn't available from any manufacturer that I know. Some people sell it on other forums or eBay. Using tank water in a drop checker carries the same risk of inaccuracy that the co2/KH/pH chart has. That's my understanding at least. I got my 4dKH solution along with a glass drop checker on ThePlantedTank's sell thread. Somebody may be selling it here though.

 

[tim_s]

I got a red sea drop checker a few years ago and it still needed 4dkh reference solution. All it came with was a small indicator liquid dropper bottle of bromothymol blue (i.e. low range ph test). Is the newer kit different?

I do not have a 4dKH reference solution in my kit, My tank is 4dKH perhaps I will use RO/DI water from a salt water tank and add baking soda.

 

[aqua_chem]

We have a sticky in this forum for making it. You absolutely can not use your tank water because as we saw before, you have other buffers present in your system that invalidate the coloring scale.

 

[tim_s]

We have a sticky in this forum for making it. You absolutely can not use your tank water because as we saw before, you have other buffers present in your system that invalidate the coloring scale.

Perfect! I will post feedback once the solution has been completed, I can produce large batches and if needed will ship leftovers for the price of shipping and container.

 

[tim_s]

Hi Everyone,

My tank is a little messy and the tannins are skewing the colors and washing them out but here is some *quickly* taken photos.

The plants need to grow in but I am working on it

 

[CorallineAlgae]

Gorgeous fish and driftwood!

 

[tim_s]

Thank you - much appreciated. Very much a work in progress, have not bothered to even clean the front glass, however, the discus are in now and watching these curious fish explore the tank really is amazing.

I will take better pictures a week or so down the road

 

[tim_s]

penang discus and red turquoise are not in any photos I just noticed, which is the most detailed fish I have LOL

Will need to add some photos tonight.