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Co2 not stable ???

gcodrutv

Member
Joined
2 May 2019
Messages
51
Location
Dublin, Ireland
Hi,
I'm using a 2kg bottle every 3 weeks. When is empty i have a replacement. bottle to avoid interruptions.
Injection is via 2 JBL inline diffusers, one is connected to a spray bar that cover all the back of the tank and one diffuser is connected to 2 return nozzles that give surface agitation.
Drop checker is yellow and in the afternoon, I can see that the danios zebra don really like the Co2 cumulation and they stay close to the surface.
Kh is 1.5 - 2 on the water change and I add 1 table spoon of bicarbonate of soda with every water change to bring it up to 2 - 3.
I attached a graph of the ph drop. The measurements are taken every hour via GHL ph probe.
The Co2 is starting at 6am and finishes at 9pm. Lighting schedule is more mother nature. The tank is in a bright room with load natural light and main lights are coming on at 11am for 50%, goes 100% from 2pm till 6pm and completely off at 10am.

I'm dosing full EI plus CaCl with MgSO4 every day via dosing pumps.
Calcium is 1am, micro is 4am and macro at 7am.

I do have loads of BBA and green spot algae on rocks, wood and starting on plants.
 

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What size tank do you have ? Mine is 500l and 6.5Kg CO2 lasts about a month
That's one long CO2/photo period not surprised you have BBA, after 4-5 hours of light plants have had their fill of light and long photoperiods are mainly for viewing, but algae will use any light it can high or low. My photoperiod is just over 7hrs in total.
Some more details will help filter/lights/ powerhead etc plus a full tank shot.
Do you have a clean up crew- snails/amanos/RCS etc
 
How big is your tank, I get through 2Kg in about 100days on 180l tank, with yellow'ish drop checker, so I would assume your tank is at least (180l x 100days / 21days) 800litre to be consuming that rate of CO2 or your have extremely poor CO2 injection and distribution.

That is a very long CO2 period along with long lighting period which could be part of the reason for algae issues. Try reducing to just 6 hours (or less) straight on, no poncing around with variable stuff (until BBA sorted) and try to reduce too much natural light getting to the tank. Plants are usually done with food/CO2 after 4-5hours, especially if the light is high, which is why you should start at say 6 hours.

You must dose macro and micro on alternate days as the iron in the micro reacts with the phosphate in the macro and precipitates out as insoluble and plant unavailable iron phosphate.

Also, really, sodium in bicarbonate of soda has no place in fish & plant keeping. If you wish to continue to add something switch to potassium bicarbonate, as least the plants can make use of the potassium.

To increase your hardness, add some form of crushed carbonate to substrate or use small doses of remineralising salts.
http://www.theplantedtank.co.uk/RO.htm

We will need a lot more tank & light & CO2 & filter and pictures to help further. :)
 
Hi all,
Thanks for your reply.
Tank size is 156cm long x 36cm wide x 60cm height, 336l volume.
Most probably the best solution is to turn off the lights completley during the day and leave them form 4pm till 10pm. Anyway in the evning the light are running at 30% only.
The tank is in a very bright room and receive abmient natural light, not direct sun.
The filtration is done by one JBL 1902 and one Oase BioMaster 600T. No poweheads (yet). I do have a long spaybar on the back.
Lights are 2 GHL Mitras 150cm.

Dosing wise, I found a dosing regime that mentioned that micro and macro can be dosed in the same day as long are few hours away.
I'll try to change the dosing regime and reduce the Co2 just until the light will be on at 4-4.30pm

Cleaning crew are 10ottos and over 70-80 red cherry shrimps.

Will upload picture with the issues and full tank.
 
Pictures of the tank
 

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That was before the cleanup. Every second day all the leaves are been pickup. Also sorry for the reflections.
I was thinking to add 2 powerheads at the end of the tank, but flow seems to be decent (i think). I do have some grass and swings nicely in the current.
The drop checker is on the left corner behind the plants and stays mostly close to yellow than lime green.
 
The current real flow reading on the filters is:
500l/h for the Oase and 710l/h for the JBL 1902
That will be 1200l/h in a 300L tank (260l if I deduct the substrate, rocks and wood). That is over 4x the volume.

Mainly the flow restriction is caused by a major design fault.
I found out yesterday that the PVC ball valves need to be next size bigger in order not to create flow restrictions.
According to VDL, the 20mm ball valve has 15mm bore hole.
All my plumbing is done using 20mm piping and the ball valve reducing the diameter to 15mm, also the hose connector are not better. I'm using 20mmx3/4" for 16/22 hose and 25mmx3/4" for 19/25 hose.
I shaved all the shoulder on the ball valve flange and I gained 10l/h extra. Not much.

Next step will be to replace the ball valves with 25mm one, Tank is bottom drilled for 2 canisters and one emenrgency overflow.
 
Tank size is 156cm long x 36cm wide x 60cm height, 336l volume.

So ignore the substrate/hardscape and you should be aiming for x10 tank size to filter/power head outputs so 3360l/h the x3.5 turnover you have is more suited to a low tech tank. The low tank turnover is probably one of the reasons your CO2 isnt stable. Fluctuating [CO2] during the photo period is one main reason CO2 injected tanks have issues. Flow is KING and yours lacks flow IMO, compounded by too long a photo period OFC. CO2 diffuses in water 10,000 slower than in air so having good flow in a CO2 injected tank is important, X10 ratio of tank size to filter output is generally accept by most but some manage it with less, I use more.

we know that when the plant senses that high concentrations of CO2 is available, it responds by reducing the production of expensive Rubisco. When it senses a lower CO2 concentration it must increase Rubisco production, however because this protein is so complicated and heavy, the increased production requires 2-3 weeks in order to change the density in the leaf to match the new gas concentration level. So it is much easier to reduce production than it is to increase production. When increasing gas injection therefore, it hardly takes any time to see an improvement in health. When lowering the concentration, the plant will suffer because it must now ramp up Rubisco production to account for the loss of CO2 availability.

When increasing the light, the plant must reallocate resources from Rubisco production/maintenance in order to deal with the increased radiation. This may entail new pigment production for protection. When the light is reduced, the plant then reallocates the light gathering proteins and can devote them to Rubisco production/maintenance.

So when we mess around with light and gas, we have some degree of predictability.
 
Hi Zeus,
Let me correct you on the above, the 1200l/h is total measured flow.
If I consider the filter advertised flow, JBL 1902 -1900l/min and Oase Biomaster 600 - 1250l/h, will give 3150l/h combined flow in a 320l brute volume tank, will give a total turnover of x9.84, that would be close enough to ideal x10 target.

If I reprogram the lights to turn on from 4pm till 10pm (viewing time) would be OK ?
Also adjust the Co2 from 6am till 6pm will be ok, the room receive a lot a natural light.

I was following your tank build for a long time, but I didn't get it why you have 2 independent line of Co2.
Same as Co2 fluctuations, I reali don't get it.
If the Co2 has the same flow 2 hours before lights on till 1 hour before lights off, is not constant Co2. I'm doing something wrong ?
This is what I was doing for long time (different forums advise).

Is getting more and more confusing.

Don't get me wrong, but I'm getting more and more confused.
Same as EI dosing method, just followed the daily dosing method.

The only thing that works is 50% water change. If I change only 25% I can see that the conductivity does not change much and comes back to original level in 36 hours. I do 50% every Friday or Saturday.
 
Let me correct you on the above, the 1200l/h is total measured flow.
If I consider the filter advertised flow, JBL 1902 -1900l/min and Oase Biomaster 600 - 1250l/h, will give 3150l/h combined flow in a 320l brute volume tank, will give a total turnover of x9.84, that would be close enough to ideal x10 target.

The x10 advised rule is for the advertised values so you should have enough. In the FTS you did was the filters & power heads on? I ask as there isnt much surface agitation IMO

If I reprogram the lights to turn on from 4pm till 10pm (viewing time) would be OK ?

Sounds like there should be plenty of light 6hrs till you get on top of the algae

Also adjust the Co2 from 6am till 6pm will be ok, the room receive a lot a natural light.

No as you need the full pH drop by lights on which normally takes 2-3hrs in a big tank.
Natural light is a BIG NO NO as you cant control it and if the tank gets direct sunlight it is very powerful, I use a big piece of cardboard to block it on my big tank or I close the curtains. On small tank I use a piece of MDF.

I was following your tank build for a long time, but I didn't get it why you have 2 independent line of Co2.

Fine tunning CO2 is a great read

I inject CO2 at a VERY high rate and a relatively low rate at the same time OK then at target pH I inject at low rate only together they get the target pH in 30mins, however the low rate would take says 5 hours.

in D Wongs graph below the high and low rates can be seen and the time it takes to yield the pH drop

upload_2019-7-5_21-55-46.png


So in the graph the low rate in stable after 5hr+ and so is the high rate, but the high rate is lethal to livestock OFC So I use both then when the high rate hits the target pH I switch it off and the low injection rate hold the pH drop.

So my CO2 setup is more like
upload_2019-7-5_21-59-51.png


D Wongs says holds like Magic, I say Magic has nothing to do with it you just need twin injection and a PLC, But his tanks are fantastic :wideyed:

If the Co2 has the same flow 2 hours before lights on till 1 hour before lights off, is not constant Co2.

yes and NO. yes because its a constant rate of injection thats all. NO because it needs to reach equilibrium which takes hours loss from the surface changes as the [CO2] increases, plants use different amounts of CO2 which is light intensity dependant and they take about 30mins to get going then after 4-5hours in high light intensity they are full so wont use much CO2. There are many variables when we say constant CO2 we mean a stable CO2 concentration ([CO2]), as its the [CO2] that controls the Rubisco production.

I'm doing something wrong ?

Yes and No it is hard to get it right - but at least your asking the right questions ;)

Read Wongs CO2 I linked not once it takes quite a few times I still read it occasionally.

Everyone struggles with CO2 at first, some get lucky OFC But IMO you have to struggle with it mess up with algae and recover to understand it

The only thing that works is 50% water change. If I change only 25% I can see that the conductivity does not change much and comes back to original level in 36 hours. I do 50% every Friday or Saturday.

I have never do a routine conductivity/ppm measurement and I have a Hanna pH pen that does it easy as in the EI method the 50% WC resets the tank so the conductivity is irrelevant- plants tell you if its working. I do clean my FX6 canister weekly keeps flow good in canister optimum which in turn helps the bacteria get plenty of O2
 
Beautiful tank mate just follow the advice given and will be all sorted but it is going to take some time
 
@Zeus. Thanks for advise and explanation. Co2 is not easy. I had this algae problem on my old tank about 5 years ago when i start using pressurised Co2, but the old tank was in a dark room and i could control the light much better. Eventualy managed to eradicate most of them.
Since I upgraded the tank (and house) the problems are bigger.
I was thinking for a good while to try your injection method using 2 solenoid.
1st on 1h before sunrise with high injection rate and once i reach ph drop turn off and keep the second for "topping off".
But i came across this article https://barrreport.com/threads/stable-enough-co2.8614/
I will try to increase surface agitation to see if will stabilize tje Co2 levels.

Also can you recommend any small wave maker that can be 0-10v controlled and won't brake the bank ?
All of them have magnets ? I can't use them because the tank is against the wall and on the left is a door to the in wall press.
 
Beautiful tank mate just follow the advice given and will be all sorted but it is going to take some time
Thanks for compliment.
Now is much better than 3 months ago. Is like a never ending story.
 
I was thinking for a good while to try your injection method using 2 solenoid.
1st on 1h before sunrise with high injection rate and once i reach ph drop turn off and keep the second for "topping off".
But i came across this article https://barrreport.com/threads/stable-enough-co2.8614/

Only had a quick read of the thread at the Barr Report and it seems its was about pH controllers which do give fluctuating [CO2] and IMO/IME i would advise folk not to use a pH controller as they need re-calibrating often and you still get pH swings. I did use a pH controller for some time on mine for the whole CO2 period and my tank suffered ph swings, then I only used it for the CO2 boost/loading period but it still need calibrating OFC. Better to spend the money on a decent pH Probe/pen IMO. The pH controllor is still on my setup but it doesnt control the CO2 injection any more as I have redesign the PLC software and all it does is record the time it takes to get the pH drop via the PLC, plus I can press a button on my PLC and the pH controllor comes on for 30mins which is handy as a quick pH check

If you are thinking of using twin solenoids like me proceed with caution as you could easy kill all your livestock, its not the cost of the extra solenoid/needle valve/atomisers/reactors thats the issue is having a decent timer thats the issuse, as cheap timers are unreliable and will lead to problems its only time as they do fail. Having a PLC which is 'a digital computer used for automation of typically industrial electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, light fixtures' they are very reliable without the use of my PLC I would NOT use duel injection. My PLC cost about £1000 but it does control my kessils on the 0-10v twin outputs also, which could also be using to control pumps that work on the 0-10v rail also

Also can you recommend any small wave maker that can be 0-10v controlled and won't brake the bank ?

They do then to be expensive and flow not ideal, which is why I went for the Maxspect Gyres 330 x2 and the Maxspect controller is pretty decent and great flow
 
Regarding the PLC, I'm familiar with them. I used to work with something like that in the past.
But been lazy, I took the easy way and make miself a nice present, I got a GHL ultimate set and dosing pumps.
I went a little too far with the setup, but I like gadgets.

At the begining I used the ph control function, but as you said, I got massive ph swings.
Now the ph control is like a safety switch, just in case the ph is dropping too low. At the moment is set to shutdown at 5.9 ph.

The GHL is controlling the lights as well and is mainly monitoring and logging everything. Is been set to send me status reports every 2 hours.

I was looking at Maxspect gyre, but they are too big and too expensive for my tank.
The tank is only 36cm (14.4 inch) wide. I think they are overkill.
My plan was to use 4 Jebao wave makers mounted on the back pointing to the front glass. They do a 0-10v, but quality I heard is not the best. That I was looking for another solution.
 
I got a GHL ultimate set

Looks like a decent bit if kit spec wise ;) it does say 'Up to 64 independently switchable sockets' How many does your have ? It might be good enough for twin CO2 injectors ! @ian_m may be able to comment on its suitability as he is the guru on gear like that round here.

I was toying with the idea of having twin solenoids and one injector myself for simplicity on a single reactor or just an intank atomiser in my 50L tank. one injection/BPS rate for pH drop then another once target is reached. I have only had the pH controler off for over a week for the pH drop and so far I've been impressed with it. target pH is 6.70pH and at the end of the CO2 period is still 6.70pH with a little drift 0.05pH over that period.

I was looking at Maxspect gyre, but they are too big and too expensive for my tank.

Sometimes you just get what you pay for I've been very impress with them so far but I got the Maxspect Gyre XF330 Double Package at a release price of £341.99 so wasnt too bad, plus was able to get rid of quite a bit of plumbing and flow SO much bettter
 
The kit is mainly used by reef keeper. I was thinking if is good for them, will be good enough for me. Is kindly like Rolls Royce of aquarium controllers. Is not cheap, but as you mentioned you get what you pay for. Is the commercial equivalent to your PLC.
I do have the power bar included in the set (5 controllable + 1 permanent) and I got a second older model with 4 controllable sockets. I still have one free socket that I was planning to use it for the second co2 valve.

How did you mount the Maxspect ? My tank is against a wall and don't have any solution to attach the magnet on the back.
They look tempting. I read your post when you get them. They are great.
I saw them in action in a reef tank. they worth every penny.
My plan was to mount them on the back and get rid of the long spray bar.
But Christmas is not far away, maybe I can convince Santa to get them...

I actually did a small experiment today.
Did a 60% water change today, after refill, add about 15ml of Easy Life Nitro and 12ml Seachem Excel and crank up the co2 to 4-5 bps.
Manage to get ph drop from 7.5 to 6.2 in about 45 min and after, adjust manually to about 1 bps. At the end of the photo period, the ph stopped at 6.11 and the plant start pearling.

Also discovered that I was mixing CaCl with Epsom Salt and was causing precipitation.
Tomorrow will mix new batches of Macro. Will separate Epsom salt from CaCl and include them in the macro solution.
I think I found @ceg4048 EI recipe.
I was using https://rotalabutterfly.com/nutrient-calculator.php to calculate the dosing.
 
How did you mount the Maxspect ?

well tank is a room divider so Only one option IMO up against the wall side by side.

I actually did a small experiment today.
Did a 60% water change today, after refill, add about 15ml of Easy Life Nitro and 12ml Seachem Excel and crank up the co2 to 4-5 bps.
Manage to get ph drop from 7.5 to 6.2 in about 45 min and after, adjust manually to about 1 bps. At the end of the photo period, the ph stopped at 6.11 and the plant start pearling.


So pretty stable in your duel injection experiment IMO. Having Duel injection makes a lot of sense to me ( I think I'm the only person doing it), but just another level of complexity and cost OFC.

Some livestock may not like a fast pH drop some folk have posted, but my livestock dont have any issues with it and I do a 1.5pH drop in 30 mins. D Wong talks about the speed of the pH drop in his CO2:Top Myths
 
My biggest issue is that i have only 5mm between back wall and tank. No chance to attach the magnets.
Do they offer some sort of suction cups ?

I'll get a second valve for co2 and give it a go.
I'm using the JBL difusers, without the extra seal and on the 1902 filter, with high injection rate almost no bubbles. On the smaller filter, i need to keep at 1-2bps not to get 7up in the tank.

What receipy of EI are you using ?
The one i have is for macro
K2HPO4 - 14g
KNO3 - 90g
K2SO4 - 46g
In 1l of water, 15ml/day.
Based on http://www.theplantedtank.co.uk/EI.htm
Micro I got them from Aquarium Plant Food UK.
When I did a water test, i got Po4 off the scale, No3 about 10 and K about 40.
Something is not right.
 
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