Question about pressurised CO2 and water disturbance

[Jose]

Clearly this is approximate as there is clearly something else in your water adding to KH and/or altering pH, as reading at the end of the table in Toms link, 16KH water with no CO2 will have a pH of greater than 8.6 and yours isn't.

What is in the water will not affect the pH drop very much even if it affects the starting pH. So dont worry if you dont see the starting pH matching that on the table for "your" kH. 1 pH drop will still be aprox=30 ppm of co2. This is the same as saying forget about your kH because you really dont know it.

 

[aaron.c]

I am having similar problems/worries. I know I need surface agitation, but how much should we be aiming for?

I have heard it needs to not break the surface, but what does this actually mean - can it be very vigorous as long as it doesn't cause bubbles on the top.

I.e - in this video I shot a while back - https://www.dropbox.com/s/19sshhmkpl2i8x5/Video 13-03-2015 18 48 18.mov?dl=0

The outlets from the spray bar are just under the surface.

 

[Jose]

I am having similar problems/worries. I know I need surface agitation, but how much should we be aiming for?

I have heard it needs to not break the surface, but what does this actually mean - can it be very vigorous as long as it doesn't cause bubbles on the top.

I.e - in this video I shot a while back - https://www.dropbox.com/s/19sshhmkpl2i8x5/Video 13-03-2015 18 48 18.mov?dl=0

The outlets from the spray bar are just under the surface.

There is no easy way to know if your surface ripple is right. You just set it at a certain ammount (eye balling) and then via pH set your co2.

 

[5678]

Jose/Ian, thank you for the detailed replies.

Am I correct then in understanding I should still see an approx 1ph drop in my tank regardless of the KH then? To help me with the setup, am I OK to use a PH test kit at regular intervals and just ignore the drop checker at first?

I'm thinking that if I turn it off for 24/36 hours and then take my baseline ph again, then turn the co2 back on and start measuring at hourly intervals this might give me the best information to work with?

 

[aaron.c]

There is no easy way to know if your surface ripple is right. You just set it at a certain ammount (eye balling) and then via pH set your co2.

I know that the two are relaetd, but I wondered if there was a concensus of the amount of surgace agitation that we should aim for, then I can adjust CO2 accordingly

Thanks Jose

 

[Julian]

Think about it, there's no way to measure surface agitation. You can't count the amount of ripples per second...

 

[Jose]

Am I correct then in understanding I should still see an approx 1ph drop in my tank regardless of the KH then?

Yes.

To help me with the setup, am I OK to use a PH test kit at regular intervals and just ignore the drop checker at first?

Yes. But I wouldnt use a ph test kit. I would use a ph pen. Even cheap ones are very good.

I'm thinking that if I turn it off for 24/36 hours and then take my baseline ph again, then turn the co2 back on and start measuring at hourly intervals this might give me the best information to work with?

Yes. But you shouldnt really need to have it off for that long. 8-12 hours should be enough, but you do need surface agitation at least for that one night, so that you find out your starting pH.

 

[Jose]

I know that the two are relaetd, but I wondered if there was a concensus of the amount of surgace agitation that we should aim for, then I can adjust CO2 accordingly

To be honest I dont know what is a good ammount. But as long as you see your surface moving slightly and no surface scum formation (this is the main point). For example if you do like ADA and you aerate at night, then any surface film that forms during the day will go away and water will be cristal clear in the morning. This way youll need less ripple during photoperiod. Also in the beginning of a tank setup surface scum is most probably going to be there IME, so maybe then you need more.

 

[5678]

Yes.

Yes. But I wouldnt use a ph test kit. I would use a ph pen. Even cheap ones are very good.

Yes. But you shouldnt really need to have it off for that long. 8 hours should be enough, but you do need surface agitation at least for that one night, so that you find out your starting pH.

I have a cheap one that I bought from ebay so will use that. I've only had it a week since calibrating it so hopefully it isn't too far out yet!

I have my co2 going off at 2030 and lights off at 2130, I have a spray bar approx 1" below the surface and what I'd call substantial surface agitation. However the drop checker is not going back to blue in that time (ends up green). To be fair, I think I am massively overdosing my co2 at present though and reaching far higher than 30ppm as it's been yellow most days (and as I mentioned in my introductions post, I've managed to gas all my fish already hence trying to get it right now before I restock)

 

[aaron.c]

Think about it, there's no way to measure surface agitation. You can't count the amount of ripples per second...

No appreciate it's impossible to measure, so we can only make crude guestimations by looking at videos of best practice (as used by others) and try to match it as best we can.

If I can get a best practice for agitation and follow it, I can remove that as a variable, and manage CO2, via injection rate

Tricky business this

 

[Julian]

No appreciate it's impossible to measure, so we can only make crude guestimations by looking at videos of best practice (as used by others) and try to match it as best we can.

If I can get a best practice for agitation and follow it, I can remove that as a variable, and manage CO2, via injection rate

Tricky business this

You're over thinking it in this regard. As long as your surface ripples at least half way across the width of the tank, you're doing it right.

 

[aaron.c]

Thanks Julian

 

[Jose]

To be fair, I think I am massively overdosing my co2 at present though and reaching far higher than 30ppm as it's been yellow most days (and as I mentioned in my introductions post, I've managed to gas all my fish already hence trying to get it right now before I restock)

main reason to use that ph pen. But leave hanging in the tank otherwise it might take a long time to stabilize the reading everytime. Also I havent seen anyone gas their fish with a 1 unit pH drop and some surface movement.

Tricky business this

Very!

 

[5678]

main reason to use that ph pen. But leave hanging in the tank otherwise it might take a long time to stabilize the reading everytime. Also I havent seen anyone gas their fish with a 1 unit pH drop and some surface movement.

Hence my thinking that I am putting way too much in at the moment. It was a stupid mistake and I was (still am!) very upset with myself for it. They had been fine for the previous 1.5 days and we popped out for a few hours on Sunday afternoon and I came home to see that I had killed them all (2 x GBRs, 6 x Harlequins, 2 x Corydoras)

 

[Jose]

Hence my thinking that I am putting way too much in at the moment. It was a stupid mistake and I was (still am!) very upset with myself for it. They had been fine for the previous 1.5 days and we popped out for a few hours on Sunday afternoon and I came home to see that I had killed them all (2 x GBRs, 6 x Harlequins, 2 x Corydoras)

Learn from your mistakes. CO2 is risky specially in the beginning. So dont put expensive fish in. Change co2 very slowly and always count BPS and pH drop. I dont really understand it when people put discus in a co2 high tech tank. Im definately not at that level of skill.

 

[5678]

Learn from your mistakes. CO2 is risky specially in the beginning. So dont put expensive fish in. Change co2 very slowly and always count BPS and pH drop.

Thanks Jose. I am trying to do just that. I foolishly rushed into it and have paid the price.

I have some more kit turning up today (more robust bubble counter, extra check valve, external heater) which I will fit tonight and adjust my system to a consistent 0.5bps.
I will measure the PH first thing tomorrow morning. and then measure it when I get home from work approx 3 hours after it has come on. I'll then adjust based on what I find.

 

[ian_m]

I know that the two are related, but I wondered if there was a concensus of the amount of surgace agitation that we should aim for, then I can adjust CO2 accordingly

You will just have to play and see.

If I angle my spray bar down/horizontal I get a green/yellow drop checker and if slightly above horizontal I get a green drop checker.

Be very careful about angling the spray bar up to far, especially on an open top tank. Many people have come home to an empty tank and wet carpet, where the water level has dropped a bit allowing a jet of water to squirt out the tank, lowering the level even more until you get loads of jets emptying your tank onto the floor...nice.

 

[Julian]

Be very careful about angling the spray bar up to far, especially on an open top tank. Many people have come home to an empty tank and wet carpet, where the water level has dropped a bit allowing a jet of water to squirt out the tank, lowering the level even more until you get loads of jets emptying your tank onto the floor...nice.

One day I'm going to go on holiday and forget about my water level dropping. The jets that come out of my spray bar reach half way across the room..!

 

[aaron.c]

That would not be ideal would it.

 

[Andy Thurston]

I would get a cheap (£10?) pH pen from ebay or whatever you can afford and monitor co2 via pH. Leave it hanging from your tank. You are aiming for a 1 unit pH drop which is aprox equivalent to 30 ppms of co2 no matter what water you have. This is an almost instant read whilst your drop checker takes at least an hour. Its also more accurate IMO. Dont worry about the chemistry, its all been put down in simple words already.

only a sucker trusts these ph pens and they fail much quicker when you leave them in the tank, been there done that. binned it after a couple of months
http://www.ebay.co.uk/itm/like/3712...3=1&ff11=ICEP3.0.0-L&ff12=67&ff13=80&ff14=108
even if they are calibrated every time you use them

(T. Barr recommends around 40 minutes if your diffusion method is good enough).

Have you managed to get your tank algae free on toms recommendations yet?
tom also has wet/dry filters to keep o2 levels up and injects co2 into a needle wheel return pump which helps lower ph faster.
decent quality gear makes it much easier to get co2 just right, why else would tom barr use high end dual stage regs and high quality metering valves. his metering valve probably costs more than most peoples entire co2 system.