Need To Unravel Confusion Pls

[elmo666]

Ok. New tank set up as per signature. Having terrible problems with bba and hair algae. I know it's somehow linked to my co2. I'm also wondering if the new nutrient rich substrate, Aquagro nutrasoil, could be leaching nutrient content into the water meaning the ferts I'm adding result in overdose.
So, to the co2. I've been adjusting it, resulting in very stressed discus, was too high. Problem I'm having is my Dennerlle drop checker isn't going lime green, it's staying mid green, so I can't rely on it. So to ph/kh calculation to figure it out. I measured my ph this morning, and was shocked to see a reading of 6. My kh is around 1 degree so I'll have to check tonight at the end of the co2 cycle to see what my ph is then. I think I've got to bring the ph up as I'm sailing close to a ph crash. Is there a simple way of accurately measuring the co2 saturation so I can get around 30ppm. Is the drop checker failing because it only reacts to the co2 gas and not the acid it creates? I don't know. I know for every action there's gonna be some kind of other reaction within the tank. I'm out of my depth now, but want to get this sorted so that I can get back to enjoying my fish instead of being preoccupied with problems. Thanks in advance for any input.

 

[TwoTankAmin]

Co2 is supposed to lower one's pH.
 
If you used a test kit whose lowest pH reading is 6, then you might be at 6 or you could be lower.
 
The way automatically to adjust the co2 in a tank is via a pH controller. You connect it to your regulator output and then set the desired pH. As long as the water is above that level the controller will let more co2 into the tank until that level is reached and then it will shut it off. If the pH begins to rise, it turns the co2 back on. I have never used one so I am not sure if they now come with a built in timer or you need to plug it into a timer so it shuts off at night.
 
I never used a drop checker either. I find that the plants will tell us when things are not right in terms of light/ferts/co2.

 

[elmo666]

Hi two tanks. When I said I was alarmed that the ph was 6, I meant that I knew it would go even lower when the co2 kicked in, and I'm aiming for a minimum ph of 6.5. I'm not quite understanding the apparent fixed relationship between co2 and ph. If one sample of water has more dissolved solids, kh or gh, then in my mind its going to take significantly more co2 to lower the ph than in a sample containing less carbonate hardness. So, how can these two samples have a similar ppm of dissolved co2? Surely one will have far more than the other?

 

[TwoTankAmin]

KH matters. But to understand tings better consider this. When one adds acids to the water it uses up the KH and then drops the pH. If you stop adding acid after the kh has gone to 0, the pH will tend to remain low. The acid will not outgas. Now when you add co2, as it dissolved in the water, some of it turns to acid and works to drop the pH, the plants want the rest hopefully. Now if you add a lot of co2 and the pH drops a bunch and then you stop adding co2, the result is different. As the plants take up the co2 and as it outgasses, the the pH rises.
 
Now consider the difference between two identical tanks in all respects except one has lots of plants and added co2 and the other does not. Think about how much you have seen the pH in your planted tanks swing in any given day from high to low. Then ask yourself if that same pH swing happened in the non-planted tank if the effects on the fish are the same.
 
The relationship between co2 and pH in the water also depends on the KH. This quote says it perfectly, it is actually from a piece on lowering the pH in a tank:
 

One safe way to lower pH WITHOUT adjusting KH is to bubble CO2 (carbon dioxide) through the tank. The CO2 dissolves in water, and some of it forms carbonic acid. The formation of acid lowers the pH. Of course, in order for this approach to be practical, a steady source of CO2 bubbles (e.g. a CO2 tank) is needed to hold the pH in place. As soon as the CO2 is gone, the pH bounces back to its previous value. The high cost of a CO2 injection system precludes its use as a pH lowering technique in most aquariums (though see the PLANT FAQ for inexpensive do-it-yourself alternatives). CO2 injection systems are highly popular in heavily-planted tanks, because the additional CO2 stimulates plant growth.

from http/fins.actwin.com/mirror/begin-chem.html
 
One way to determine one's co2 level is by by testing both the KH and pH and then using a table like this one http/www.barrreport.com/showthread.php/12022-CO2-pH-KH-table
Scroll down the thread for the directions etc..

 

[elmo666]

Thanks two tanks. I've looked at the table, and do understand all you've said. What I want to do is set my co2 rig at the right output and leave it, as I'm preoccupied with it at the moment. I need to set it right to rule it out as a contributing factor in the algae issue I have, both bba and long filamentous algae. I'm not looking for exact precision, I know I'll never get that as its a natural environment and things are constantly in a state of flux. I'm just aiming for a safe constant level that is correct for the plants, stable enough not to risk fish health or encourage algae. Your input is appreciated.

 

[elmo666]

Quick update. I'm going to attempt to raise my ph to 6.5 at the weekend, and simultaneously my kh to 4 degrees. Once I know I've got that stability I'll focus on getting the co2 level right.

 

[eaglesaquarium]

The issue with the drop checker may be the solution of water you are using to turn the color. I believe the solution for the drop checker is a specific water chemistry for the easiest results. I can't remember what that solutions chemistry is though, but I know it's not tank water.

 

[elmo666]

Cheers eaglesaquarium. The denelle kit comes with ready made up vials of solution, about 5ml, you just break the seal, pop it in the checker and away you go......in theory lol. I've tried putting it in different positions incase the flow around it is an issue. I'm at the point where I'm thinking of getting something else. It stayed a mid green colour even when my discus were extremely distressed, hanging at the top, dark and breathing heavily. Thank god I glanced at the tank on my way out so I was able to do something about it.

 

[eaglesaquarium]

It could be the brand you are using as well.  I used two different ones in the same tank, and they never gave me the same results, even when they were placed side by side.

 

[elmo666]

You could be right. I had a couple of situations on my previous tank when my wife called me alarmed at the way the discus were acting. Each time I simply increased the surface movement and all was well an hour or so later. Each time there was no notable change in colour within the drop checker. I've had my co2 off for two days now as I'm using eSHa algae treatment in an attempt to get on top of that problem. The colour in the drop checker hasn't changed at all!! Strange....not impressed.

 

[ericNH]

Elmo I sympathize with your anxiety over your stressed out discus.  I can't offer any advice as hi-tech is over my head, but I can wish you luck.  Good luck!

I can't resist.  I recommend you ditch the CO2 bubbler and just use Flourish Excel.

 

[elmo666]

Hmmmm, that's a thought. I've invested £130 in the pressurised co2, so I'll try and sort it. That said, I wont flog a dead horse so to speak, so if I fail I will go down the liquid route.

 

[eaglesaquarium]

The good news about the liquid is that it acts almost as an algaecide to an extent, the bad news is that some plants can be sensitive to it.

 

[elmo666]

Haha, there's never an easy solution my friend.

 

[TwoTankAmin]

I have a confession. I pushed gas into one tank for just over 11 years. I never had a drop checker nor used a pH controller. I never turned it off at night and did not do anything to outgas the co2 either. Early on I tried using the pH/KH test method but it is a pita and gets pricey over time and has drawbacks. But what I learned is if i did not try for the perfect maximum level of co2 but ran at a rate that did not appear to hurt anything and was certainly helping the plants, it went fine. Over the years I found out my bubble count should not exceed 1 bps aka 60 bpm and it needed to be, at the very least, 1/2 that. But back then I was spending money on things I had to have and a pH controller was not on my list.
 
It will make things more mindles,s but like anything else in life there are never any guarantees.