I think something is wrong with my set up plants don't grow

[tovtm]

no problem I will upload some pictures tonight.
matter of fact Clive I think I slightly underestimated tank volume it is elongated 4ft long 12" wide and 18" high for some reason had 125ltr in my head :s

my co2 is at a level where towards end of the day the fish seem to be on there limits. if I changed co2 time to earlier so lime green as lights come on what's the earliest I could potentially turn it off before lights go off so for example could I turn co2 off a maximum of 3 hrs possibly 4 hrs?
thanks Clive

and would I be correct that the only reactors available for fx5 size piping would be custom home made reactors?

 

[ceg4048]

OK, well that's closer to 170L or 45USG, but anyway, 4foot is a long distance even though the FX5 is certainly muscular. Is it filled to the brim with media? What kind? You might be able to remove quite a bit of it if you needed more flow and if you had it filled with ceramic noodles for example.

if I changed co2 time to earlier so lime green as lights come on what's the earliest I could potentially turn it off before lights go off so for example could I turn co2 off a maximum of 3 hrs possibly 4 hrs?

Yes, absolutely. You really only need 5 hours or so of injection, but it's super important to have it at the most critical time. After the solenoid goes off there is still plenty of CO2 in the water and the plants don't really care too much in their "evening". If you don't have top notch CO2 at lights on, they are weakened and have to play catch-up. Also, better distribution with an in-line device will mean more even distribution and that you can use less. When you have poor distribution the plants beds have a low concentration of CO2 and where the fish are swimming there is high concentration. And it's not like the fish know what area's to avoid. They have no idea what's happening to them.

So normally when you have the classic combination of low growth performance but suffering fish, this points immediately to poor distribution techniques.

and would I be correct that the only reactors available for fx5 size piping would be custom home made reactors?

Yeah, I think so. I think it's a 25mm ID corrugated hose right? There may be a commercial reactor for that size, but if so I don't know about it. I reckon DIY is the way to go here, or, you could just port the gas directly into to the filter intake. I'd try that first. I think the FX5 has some kind of cyclic "Burp" mode which purges gas, so I think you're OK there as far as gas buildup.

Cheers,

 

[Ady34]

Yes, absolutely. You really only need 5 hours or so of injection, but it's super important to have it at the most critical time. After the solenoid goes off there is still plenty of CO2 in the water and the plants don't really care too much in their "evening". If you don't have top notch CO2 at lights on, they are weakened and have to play catch-up.

Cheers,

This is really interesting, and may answer a question I once asked about plants and their photosynthesis cycle in our aquariums.
Our tanks are more often than not illuminated by a single point, non dimmable source which gives a constant lighting intensity throughout the photoperiod. Even with this in mind do the plants still have a reduced need for co2 in the 'evening' phase?
Off gassing can also be quite rapid especially for those who use a decent amount of surface agitation so is it still ok to switch off the gas after 5 hours of say an 8 hour photoperiod? As long as its optimised for lights on.
I suppose im really asking do plants naturally reduce their need for co2 even with a constant light intensity?
Cheers
Ady

 

[Jason Greenslade]

You really only need 5 hours or so of injection, but it's super important to have it at the most critical time.

I notice that Ady has also remarked on the above comment from Ceg, but it is, for me, the most revealing and important statement about CO2 that I have ever learned. So thanks CEG, cos lime green at lights on has never been a priority for me yet, but I think if I do this it will help a lot. Will it help eradicate the small (and I do mean small) amount of GSA that I have on some of my crypt leaves too ? (sorry for the 'hijack').

 

[ceg4048]

Hi,
A couple of different issues, in general, the main point is that when the lights go on the plant tissues have spent the previous night using only oxygen, so the tissues are not saturated with CO2. The job of the enzyme Rubisco is to collect CO2 and to transport it to the reaction centres where sugar is made. Light actually damages the plant, but with good CO2, food is produced and the damage is repaired. The sooner CO2 is made available the better. In fact, most peoples problems occur in the morning. In the morning the CO2 is low, the plant suffers deficiency and hours later the CO2 catches up, but the damage has already been done hours previously.

GSA is a symptom of poor CO2, but can also be a symptom of poor PO4 --- or a symptom of both deficiencies. It's entirely possible therefore that poor CO2 in the beginning of the photoperiod triggers the GSA. Again, GSA is tricky, and since there are so many PO4 haters out there who think that PO4 needs to be limited, and who don't realize it's the third most important nutrient, also suffer PO4 shortfalls, so this has to be properly addressed as well as the timing of CO2.

About as much work is done in food production by the appropriate enzymes and proteins the first half of the day, and the plant has other things to do, so a few hours of excellent CO2 will allow them to produce the food they need and they actually start to shut down the food production in the late afternoon/early evening. Within limits the lighting won't be too much of a problem. Of course, the key is "within limits". If the plants are overdriven with lights like some zealots tend to do, then this changes the equation and failure can occur. And if you drive off the CO2 with too much agitation then this also changes things. What I'm saying is that the natural cycle is for food production to occur early and other processes to take over and the end of the shift. For an 8 hour photoperiod, I seldom have more than about 5 hours of light+CO2, but of course, I have to turn the gas on way before the lights in order to ensure CO2 saturation of the water by the time lights come on, so I wind up having 8 hours of CO2 even though the two coincide for only 5 hours.

Cheers,

 

[Martin cape]

Hi Clive,

Sorry for hijacking. My co2 is on for 3 hours before lights on, and goes off 2 hours before lights off. Lights are on for 6 hours.

When lights go on, the checker is green, maybe darkish. But I thought the checker took 2 ish hours to respond, therefore the colour of the checker 2 hours after lights on (lime green),was infact the level at lights on?

 

[ceg4048]

Hi Martin,
Well the rate and direction of movement of the gas into and out of the DC are going to vary based on temperature and other factors, so really it's best to have the lime green colour at lights on. The 2 hour number is a rule of thumb that makes us aware not to put 100% faith in the DC indication. Unless we have a £1000 CO2 meter that can generate a reading in a few minutes we really don't know what the CO2 value is. Also, as I mentioned, we don't even know what the concentration profile is in each tank. We just know generally that the concentration is higher away from the plant beds. People automatically assume that when their DC is green it means 30ppm CO2 everywhere, but nothing could be further from the truth. At the surface of the tank the concentration could be 30ppm but at the plant bed the value could be 3ppm. Gases just don't behave the way we like them to, so we "belt & brace" it with the rule of thumb of lime green at lights on (which doesn't even guarantee anything if distribution is poor). Sorry...

Cheers,

 

[jack-rythm]

Clive.. I take I you don't bother with a DC?

Sent from my GT-I9100 using Tapatalk 2

 

[Jason Greenslade]

Hi Martin,
Well the rate and direction of movement of the gas into and out of the DC are going to vary based on temperature and other factors, so really it's best to have the lime green colour at lights on. The 2 hour number is a rule of thumb that makes us aware not to put 100% faith in the DC indication. Unless we have a £1000 CO2 meter that can generate a reading in a few minutes we really don't know what the CO2 value is. Also, as I mentioned, we don't even know what the concentration profile is in each tank. We just know generally that the concentration is higher away from the plant beds. People automatically assume that when their DC is green it means 30ppm CO2 everywhere, but nothing could be further from the truth. At the surface of the tank the concentration could be 30ppm but at the plant bed the value could be 3ppm. Gases just don't behave the way we like them to, so we "belt & brace" it with the rule of thumb of lime green at lights on (which doesn't even guarantee anything if distribution is poor). Sorry...

Cheers,

Would you say, from this, that an external diffusor, or "better still" a reactor, would give a greater chance of adequate CO2 distribution (given suitable means of flow) than an internal diffusor ? (Based on the thought that if the gas is already quite well dissolved rather than in bubble form, its going to be easier to ensure its proper distribution.... bubbles rising immediately to the surface being one less thing to worry about). Or am I barking up the wrong tree with that?

 

[tovtm]

OK, well that's closer to 170L or 45USG, but anyway, 4foot is a long distance even though the FX5 is certainly muscular. Is it filled to the brim with media? What kind? You might be able to remove quite a bit of it if you needed more flow and if you had it filled with ceramic noodles for example.

Yes, absolutely. You really only need 5 hours or so of injection, but it's super important to have it at the most critical time. After the solenoid goes off there is still plenty of CO2 in the water and the plants don't really care too much in their "evening". If you don't have top notch CO2 at lights on, they are weakened and have to play catch-up. Also, better distribution with an in-line device will mean more even distribution and that you can use less. When you have poor distribution the plants beds have a low concentration of CO2 and where the fish are swimming there is high concentration. And it's not like the fish know what area's to avoid. They have no idea what's happening to them.

So normally when you have the classic combination of low growth performance but suffering fish, this points immediately to poor distribution techniques.

Yeah, I think so. I think it's a 25mm ID corrugated hose right? There may be a commercial reactor for that size, but if so I don't know about it. I reckon DIY is the way to go here, or, you could just port the gas directly into to the filter intake. I'd try that first. I think the FX5 has some kind of cyclic "Burp" mode which purges gas, so I think you're OK there as far as gas buildup.

Cheers,

5hrs injection actualy makes things so much clearer to me as I've always tried to juggle what time it should start and end and then injection rate to suit fish health but makes sence for a guide 5hrs so first of all make injection rate to a point fish are not suffering in a 5 hr time period then keep moving co2 start time to an earlier time until it reaches lime
green on lights on/yellow.

The FX5 is filled with ceramic media little peat and sponges. I know you know hell of alot more than me but I not sire it's now a flow problem all plants even on substrate move in the flow quite a bit infect I've had to open the end of the spray bar slightly to decrease the flow as when I got the fx5 and turned it on it created a 4ft long spinning washing machine lol plants ripped up fish couldn't swim and substrate started churning up at front of the glass and all got swept around and around like a washing machine lol so I've now limited the flow to a point it's just on the verge of moving the substrate around.

I did have the co2 ceramic diffuser placed directly under the inlet of the fitter but on page one there was a little say about it may not be good place to have it but as you mention placing it where I had it i moved it back last night. the fx5 has a gas collection and release cycle every 24hrs so yer any co2 eft it burps it out every day.

does my EI mixture look ok to you Clive on previous page there was some discussion about I may be dosing too much causing slow growth.

 

[ceg4048]

Hi,
It depends on the size of the bubbles, believe it or not. When the bubbles are in a very fine mist, or fog, then the gas absorption rate is high, as the mist makes contact with the leaf tissue. If the bubbles are too large then, yes, they just escape right out the top and do not have enough dwell time to be very effective. The greater the water volume the more difficult it becomes to dissolve and saturate, so higher injection rates are called for, which can then be problematic for livestock. A little bit of a Catch-22. An inline device generally works better for medium and large tanks. The Up Atomizer combines both principles by creating a mist and by also being installed inline. Many find this to be effective, but many are also annoyed by the visual of the mist, so they opt for other inline devices which dissolve the gas without the mist.

Clive.. I take I you don't bother with a DC?

The DC is a guide Neo. It can show you the path. It might be as easy to take pH measurements and to monitor the change in pH over the duration if you have a pH monitor, but if you don't have a pH meter then it becomes annoying to measure using reagents. So the DC is a quick visual reference, but one shouldn't become hypnotized by the DC. Until someone becomes adept at reading the tank itself then I would always suggest that it be used. Use it to corroborate the other sensor data that you receive. The best sensors of course being your two eyeballs.

Cheers,

 

[ceg4048]

I've had to open the end of the spray bar slightly to decrease the flow as when I got the fx5 and turned it on it created a 4ft long spinning washing machine

Well that's the good news if you have energetic flow, because that's one less thing to worry about. Are the holes pointed horizontally towards the front?

When you mount the diffuser near the filter inlet, do all the bubbles enter the tube? It's not enough to just be near. The filter has to suck up all the gas.

does my EI mixture look ok to you Clive on previous page there was some discussion about I may be dosing too much causing slow growth.

Well, I think in this case you need to fix CO2 first and to worry about everything else later. It's always possible that there are multiple issues occurring in a tank but poor CO2 is 95% of all problems. Take care of that and cross the nutrient bridge when you get to it, I reckon.

Cheers,

 

[tovtm]

holes point horizontally to the front of the glass spray bar sits about 1.5" below water level and surface movement is very minimal. the co2 al gets sucked into the inet as the inlet is on a 45 degree angle diagonally across side of the tank so the intake holes spread quite a area over the diffusor bloody noisy though where the co2 is obviously bouncing around first bend of the inet pipe lol. I will actually be amazed if something as simple as starting co2 alot earlier make my tank plants better something as simple as that lol

 

[ceg4048]

I wouldn't be amazed at all, but lets see how it goes for this first step. I would suggest adding liquid carbon as a supplement but I don't think your Riccia would appreciate that.

Also, please take pH readings throughout the photoperiod when you have time at home, maybe once per hour. This will tell us how the gas is behaving.

Cheers,

 

[tovtm]

will do won't be until weekend I be able to do that and will report back

 

[Ady34]

Hi,

About as much work is done in food production by the appropriate enzymes and proteins the first half of the day, and the plant has other things to do, so a few hours of excellent CO2 will allow them to produce the food they need and they actually start to shut down the food production in the late afternoon/early evening. Within limits the lighting won't be too much of a problem. Of course, the key is "within limits". If the plants are overdriven with lights like some zealots tend to do, then this changes the equation and failure can occur. And if you drive off the CO2 with too much agitation then this also changes things. What I'm saying is that the natural cycle is for food production to occur early and other processes to take over and the end of the shift. For an 8 hour photoperiod, I seldom have more than about 5 hours of light+CO2, but of course, I have to turn the gas on way before the lights in order to ensure CO2 saturation of the water by the time lights come on, so I wind up having 8 hours of CO2 even though the two coincide for only 5 hours.

Cheers,

Thanks Clive.
I struggle to find the balance between happy fish and the right co2/light balance for my plants. I now have my co2 coming on 4hrs pre photoperiod and off 1 1/2 hrs before lights out. This is using a slower injection rate which provides 'optimal' co2 for lights on and maintains a safe level throughout the photoperiod for fish whereby usage and off gassing keep concentrations from rising to toxic levels. This gives me an overlap time of 6hrs gas and lights.
My lighting is raised quite high above the tank and growth is very slow so I don't want to raise it any higher to help with co2....id actually like to speed things up but cant seem to get enough co2 into the tank when i do. I think, given your advice above, and that plants do their food production first, I may try and improve things further and ensure excellent concentrations for lights on, but switch it off maybe half an hour earlier. Would you suggest just increasing co2 injection or is it best to play safe and just turn the gas on even earlier? Can there be any detrimental effects to switching co2 on 41/2 hours in advance of the photoperiod? Like greater sensitivity to co2 due to reduced O2 levels from the night period?
It's so frustrating, as I want to achieve faster growth, which means greater lighting intensity, but I can't seem to get enough co2 in the tank when I do this and have happy fish. I'm considering trying the reactor method to see if it improves things for me.

Funnily enough the other day I did a water change before the normal photoperiod. It took about 2 hours due to one thing and another, and I'd switched the lights on to see what I was doing....co2 was not up to levels and the very next day I had crypt melt! Obviously from blasting them with light without the appropriate co2 🙁 these are definitely my tester plants as they react first!

Cheerio,
Ady.

 

[Nathaniel Whiteside]

Hey chaps,
Ady, My co2 comes on 3 hours before and goes off two hours before.
Mines to do with good surface agitation. But I do find If I run my Co2 at lime/yellow, the fish seem a lot more comfortable and are not breathing as heavy as if I ran the DC at mid green.
This obviously is due to the high dissolved oxygen levels in the tank from pearling plants.

Funnily enough, I've never experienced crypt melt, and I'm not the most regimented of aquarists. If you get me lol.

Cheers,

 

[Ady34]

Hey chaps,
Ady, My co2 comes on 3 hours before and goes off two hours before.
Mines to do with good surface agitation. But I do find If I run my Co2 at lime/yellow, the fish seem a lot more comfortable and are not breathing as heavy as if I ran the DC at mid green.
This obviously is due to the high dissolved oxygen levels in the tank from pearling plants.

Funnily enough, I've never experienced crypt melt, and I'm not the most regimented of aquarists. If you get me lol.

Cheers,

I'm beginning to wonder whether I could drop my lights and forget about the crypts. Unfortunately they are shade plants so being out in the open like they are in my tank maybe they will be more sensitive to change in light/co2? I ran my first planted tank attempt with the lights right above the tank and had reasonable success, so I'm stumped really....maybe the crypts have just got addicted to the current level, but may adjust and come back again if I increased lighting intensity and they melted?
Another thing like you allude to is maybe plant choice. If I had lots of fast growing stems would they balance the co2 better and allow greater injection rates by using it faster and saturating the water with oxygen during the photoperiod. I tried to cover this base too though by having surface agitation for better gas exchange......
Don't get me wrong, the tank is ticking along, I'd just like the option to be able to put it into overdrive!
Cheerio,

 

[ceg4048]

Well, as mentioned, CO2 injection is a Catch-22. You'll need to play with it in order to find how to accelerate without annihilating the fish. 4 hours prior to light is an unusually long time. Try a higher injection rate for less "pre-light" time and shut the gas off earlier by the same amount of time. There is no way to avoid the initial discomfort of the fish, but they adapt to the higher injection rate within a few hours if you increase the rate carefully. Don't panic at the first sign of discomfort. Try this on your days off when you have the time to monitor.

The usage rate falls off as the day goes on, so as the CO2 dissipates from the water column when the solenoid closes, the uptake rate also declines. This gives the fish a break so they are more able to tolerate a higher injection rate. If you then increase the light intensity during peak uptake time, the plants will remove more CO2 from the water column. The uptake rate is not just a function of whether the plant is a stem or not. It also depends on the plant biomass because every cell must burn sugar. Crypts have a huge mass both above the substrate and below, because they have a massive root structure which also must be fed sugar. So crypts use a lot of CO2, and that might be one reason they are so sensitive to poor CO2. I imagine the melt is a clever way to quickly reduce the biomass in order to reduce the uptake demand. That's just my theory though. I do not really know the answer. What I do know is that there is correlation between melt and CO2 status. Crypts also do very well in non-injected tanks, but that happens after they make the physiological adjustments to become more efficient at low CO2 levels. So I don't think there is any value in prioritizing the avoidance of this plant or that plant. Each person must solve the riddle of CO2 in their particular tank and then they can grow anything desired.

Cheers,

 

[tovtm]

Hi Clive done PH tests as much as I can today. They are as follows hope it means something to you


2pm (1hr before lights on) PH 7

3:45 (45mins after lights on) PH7

5pm PH6.5

6pm PH6.5

7pm PH7

9pm Ph7.5