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My pH profile

Mine angles up slightly (not enough to shoot it out of the tank should I spring a leak!) so I get a decent surface agitation without breaking the surface. After weeks of messing around I found this the best balance at the expense of having to raise bubble rate a smidge. A few extra pennies in gas here and there for the wellbeing of the fish is not a problematic compromise for me.

But I accept it is all hard work. I once did my water change and filled like an extra 5mm which reduced surface movement significantly and the difference to fauna was quite notable. So i've found even taking off spray bars to clean, or doing water changes etc I'm always paying critcal attention to return things to how they are when it all 'works' lol 🙂
 
If it angles up, then doesn't the Co2 through the spray bar just go straight to the surface and gas out of the water...
 
No, there's a clear supply of co2 getting blasted down the front pane. It's a tetratec 1200 with about 50% media removed in 125l tank providing the cojones lol
 
Sacha said:
By the time the fish tell you, they are already suffering. Ideally I Don't want to get to that point
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This is not true at all. If you are monitoring the tank, as suggested, and if you see the fish in distress, all you have to do is to perform a massive water change. The fish will begin to recover immediately.


Sacha said:
Just out of interest, what angle is your spray bar pointed at?
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Spraybars should be pointed horizontally.


Sacha said:
I will switch back to my atomizer then. Although I really don't like the micro bubbles that it chucks out. I don't think my flow can possibly be poor. I have (rated) 2400 lph on a 125 litre tank.
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You don't have to use the atomizer. You can simply port the gas into the filter suction tube and let the filter be your atomizer.

Cheers,
 
Here is a pH profile for today:

syq9.png


12:00 = Co2 ON

14:00 = Lights ON

20:30 = Co2 OFF

22:30 = Lights OFF


I increased the bubble rate and had the Co2 come on a bit earlier.

At around 19:00, I got the sense the fish were a bit uncomfortable. So I reduced the bubble rate.

The drop checker is also yellow, if that means anything.

Does this look any better?

I know that those pH/ KH charts can't be trusted. However, according to those charts, my Co2 is way above lethal levels.

Will be switching back to the in- line atomizer over the weekend probably, and will do another profile next week.
 

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All this messing with c02 WILL result in bba...just be very careful messing with it, as Clive states, if it ain't broke don't fix it.

I'm going to let you into a little secret now. I have never used a drop checker as I couldn't read them very well, as I do have a little colour blindness. I monitored everything very closely at the start. Six years later and I've never lost a fish to c02 related problems. I also just set my bubble rate to 1-2 bps and just leave it. Ime plants like a consistent amount of c02, any change will result in c02 related algae.
 
Thank you Ian.

What prompted me to make this change was the fact that I see a lot more pearling in other tanks than in mine. Also I know I should be seeing a larger drop in pH than I am seeing. Will switch back to the inline atomizer, do a pH profile then, and post it on this thread.
 
This is the best thread I've read on ph profiles: Tom Barr and others put forward some nice profiles and how to achieve them. The emphasis is on establishing a nice equilibrium ph profile / dissolved CO2 conc throughout the light period: CO2/pH level in planted tank | Page 2 | UK Aquatic Plant Society

I learnt a lot from this and by following the links / suggestions.
 
OK so this is what I have learned so far:

My pH profile is too "pointed". I want a more flat, constant pH profile.

Ideally I want the pH to reach its lowest point around lights on, and stay there until a couple of hours before lights off, when it should start to rise again.

The easiest way to achieve this is to increase the bubble rate, while creating some surface agitation?

Is that really the only way to achieve the "flat" profile I want- I have to gas out some of the Co2?
 
...yep, by matching gas in and gas off you reach a constant level. Higher rate + surface agitation is one way, particularly if you want to drive the gas off at night.

What I do though is low surface agitation / much lower rate (start a couple of hours before lights on) with no gassing off at night. Before injection in the morning this means there is still some CO2 kicking around and means I don't have to inject as much CO2. There is no distress to the fauna 24/7. I inject inline which gives me good dissolution and distribution around the tank.

First try higher rate with higher surface agitation as this gives you more margin for error whilst you are finding the balance points (airstones don't cut it, you need a powerhead to break the surface and get good gas interchange), and plot a PH profile, hopefully you'll see for yourself how it plateaus at a given rate.

If you want pearling make sure the plants have all the nutrients they need. Phosphates would be my tip to try adding a bit more of, but don't skimp on any of course!

cheers
 
Hey guys,

This thread (and those linked) have been so helpful. Thanks!
My current profile (125 litre aquarium, UP inline atomiser, ~3 bubbles per second): -

Rot41Ri.png

I think in my case, surface scum was interfering with the gas exchange (even though I had a Koralia blasting the surface). I've replaced the Koralia with an Eheim Skim 350 and now there is a ~1 pH unit drop before lights on which then levels out and doesn't distress the fish.

P
 

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That looks about perfect well done!

Another thing to note is that any change in pH caused by plant uptake of CO2 seems to be minimal to non existent compared to the gas in / off equilibrium...ie it still plateaus no matter what the level of photosynthesis...
 
Thanks 🙂
NatureBoy said:
Another thing to note is that any change in pH caused by plant uptake of CO2 seems to be minimal to non existent compared to the gas in / off equilibrium...ie it still plateaus no matter what the level of photosynthesis...
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I wonder how much CO2 the plants produce by respiration? Even with all the surface agitation, it seems to take ages for the pH to rise.
 
hmm looks like an exponential fall in pH and then a natural logarithmic climb in pH...where's the geek symbol?
 
When I had canisters on my tanks I measured about 20 ppm of CO2, when I switched over to wet.drys, I had 3 ppm of CO2 at the night time.
Scum on the surface, quite a few things can mess with it.

What you want is an ideal mesa like concentration:
e04a2b72.jpg

Your CO2 is more like this: but not as high to reach the lethal thresh hold. Basically you likely only have 15 ppm or thereabouts.


1a3e225f.jpg


You can make the mesa shape and get the CO2 up faster with better mixing, more flow etc, and with a higher CO2 bubble rate etc.
BUT...........you do not want to hit the lethal thresh hold. So go slow and consider several ways to add CO2 up to a point, then it's "wasted". This will give you a nice mesa shape without any controllers(which is yet another method to do it).

A single action purge tube inside a reactor will do this quiet easily, basically the reactor will dissolve 100% of the CO2 up to a pre set level inside the reactor. Gas builds up later in the day cycle and this can purged, or wasted as a mist.
Typically the last 1/2 or less of the lighting CO2 cycle.

the height inside the CO2 reactor can be adjusted to suit also. Some chose 1/2 way down, some chose 3/4th etc.

Works just like a regular reactor unit till the level reaches the rigid air tubing you add and this has an airline that loops back to the main filter pump etc and sucks the gas in and spits it out into the tank.
 

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Here is a pH profile I made today:

2z4jorq.jpg


12:00- Co2 ON
14:00- Lights ON
20:30- Co2 OFF
22:30- Lights OFF

This is with quite a lot of surface agitation now (made by internal filter's pump), and the in- line atomizer.

How can I flatten this out more?
 

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