Between/within variation

[CrispyCod]

Hi all,

I had a query regarding requirements for c02 levels...

I have read various posts regarding fluctuating c02 and it causing algae. My question is regarding what do we mean by fluctuating? Some say keep it stable throughout the lighting period, some say, as long as it is ok at the start of the period, it doesnt matter if it increases through the day...

So what exactly does this mean?

1) Fluctuating within a day? (going up and down, due to poor/inconsistent flow etc)
2) Fluctuating between days? (Different levels on different days) ( NOT experienced)
3) Fluctuating from end of day 1, and start of day 2. (yellow at end of day 1, lime green at start of day 2)

The reason I am asking is that I am experiencing algae which is caused by fluctuating levels (BBA).

I currently have version 3) in my system, could this be the cause of the BBA? or is it more likely to be related to the flow/distribution characteristics of my tank? I have found it very difficult to get the timings and rate right such that the level is correct at lights on and stays at this level for the duration of the day...

I am interested to know if the plants have some kind of 'memory' in terms of uptake so the plants would expect the last experienced level the following day, or do they reset for each new day?

Interestingly the algae starts as brown edges on older leaves, which then if left leads to BBA. The brown does not rub off in any way. I have seen a post with a similar problem but it was never answered. I will post this part in the appropriate area of the forum.

Thanks for the help.

Chris

 

[CrispyCod]

Nothing? No- one?

 

[omen]

It's been my experience that fluctuations in a c02 injected system generally occur whenever the c02 cannister, or fire extinguisher is running out. As the pressure drops the amount of c02 entering the tank drops. I find this is the time I will get BBA, and will occur over a few days.

It's very difficult to address why you are experiencing algae on a regular basis without knowing more information about your tank, lighting etc.

 

[Ady34]

Hi there,
getting c02 correct is difficult, getting lime green dc for the lighting period is essential from what i have learned from more seasoned plant growers. Also what is essential is the correct distribution of the c02 (as it is for ferts). To be able to comment more precisely we would have to also know your lighting amount and period, however...

1) Fluctuating within a day? (going up and down, due to poor/inconsistent flow etc)
2) Fluctuating between days? (Different levels on different days) ( NOT experienced)
3) Fluctuating from end of day 1, and start of day 2. (yellow at end of day 1, lime green at start of day 2)

The reason I am asking is that I am experiencing algae which is caused by fluctuating levels (BBA).

I currently have version 3) in my system,

Presuming your not adding huge amounts of light, I think your current dc is almost perfect as lime green for start of the day is good, and going towards yellow is ok as long as the livestock is coping. But more light = more c02 requirements therefore more injection necessary and possibly too much for the fish.
I would suspect therefore that your bba issue is more down to the flow/distribution of the c02 around the tank. Have you tried placing the dc at various points within the tank to see if the dc responds the same? Also what is your water volume, filter turnover, and are you running extra circulation pumps? Do you have a spraybar attachment or standard filter returns?

I am interested to know if the plants have some kind of 'memory' in terms of uptake so the plants would expect the last experienced level the following day, or do they reset for each new day?

I have recently read some information from posts from Clive (Ceg) which state that plants are like junkies, they get hooked on a particular level of co2 and if that reduces they respond badly, however i think that lime green dc for lights on is fine, maybe try slightly reducing the rate of injection but extending the pre lights on injection period to get a more consistent delivery and maintain lime green throughout the whole photoperiod rather than getting to yellow if your worried about this.
It would be helpful to know more about your lighting and flow though.
Hope this helps,
Ady.

 

[CrispyCod]

Hey Everyone,

Thanks for the replies,.

In answer to your questions...

Tank size 128L
Lighting period: 6 Hrs
Lighting: 3.1WPG
Flow: Just over 10x, spray bar configuration, Removed power heads, as read that in areas of very high flow can cause BBA ( which was the case)
Dosing: 1.5 x EI, based on James planted tank calculator.

i know the lighting appears high, but have kept the period to a minimum, the reason it is so high is that my previous lighting arrangement was not long enough for the tank, and had an almost spotlight effect, where the edges were very dark. so to extend the lighting to the edge of the tank, the wattage also had to go up. From reading though, 3WPG is not a ridiculous level to have, it just makes things harder. At the end of the day it should be possible to maintain a vibrant healthy tank under those conditions, I just need to figure out what I am doing wrong with the other areas...

I think the C02 question has been answered in that having it increase over the course of the day should not be a problem. As long as it doesnt exceed the safe level for the fish.

I will repost my BBA question in the other forum, it has been a long standing issue, which i am running out of ideas how to solve, plus no one else seems to have the same symptoms!

Thanks again for the help

Chris

 

[Ady34]

posted in the algae section, i think too much light. Id reduce the intensity of the lights rather than the photoperiod, with high light comes higher demands of c02 and if there isnt enough c02 the plants will lose to the algae.
Cheerio,
Ady.