BBA and CO2 Strategy

Paul G

Lifetime Charter Member
Lifetime Member
Sep 28, 2011
142
32
28
Independence MO
Hi All;

Have recently been experimenting with O2 and CO2 tensions and ways to monitor them. I have also been very happy with having been algae-free for some time.

Tank is a 210 gal 72" x 24" x 24". The system is three years old. It has been through various stages, including bouts with BGA. Never before BBA, which has started to show up on the wood and dead and dying leaves. I am not overly concerned because I think I can nip this problem before it gets out of hand. Given the tenacious reputation of this blight, however, I need to seek help to guide my decisions.

I have no cyanobacteria on stem plants or anywhere else I can see, and have not had for some months. There is just a little GSA, perhaps somewhat fuzzy, on a few of the Ludwigia leaves that are just at the very surface, closest to the light. This I expect to see. Nowhere else do I see algae of any kind - except the BBA.

I had been keeping the pH at 6.89 with a KH of 6 degrees. I decided to depress the pH to 6.84 to increase the CO2 tension. I also cut back the 8000 Kelvin full mid-day illumination (very bright LED arrays) to one-third, along with about 200 watts of T5HO 6700 Kelvin. The difference in the light is significant. Photoperiod is 12 hours, bracketed with 40 minute twilight times.

I also am adding 100 mL SeaChem Excel daily.

The BBA has set in on the old, tattier leaves of the Microsorum and the wood. Small tufts trying to get a hold on the edges of the Anubias leaves and on some rocks appear to be going away - for now.

If not beating it back, I am at least containing it for the moment. I have little doubt that the CO2 increase is a significant factor. I have noticed that as the CO2 level has gone up, so has the dissolved oxygen, and also a noticeable increase in plant vitality overall. And, no new tufts of BBA.

I have a lot of macro in there. Potassium is well in excess of 3 ppm from previous heavy dosing. Nitrate is between 10 and 20 ppm. Phosphate is just under 5 ppm. These derive from fish waste and I have little control here. I have not deliberately dosed macro for some time. Buffering agents are both calcium and magnesium salts, so I do not suspect magnesium deficiency, although I have not tested for that.

For the time being, should I stop dosing iron and micros? I have been keeping iron at .5 to 1 ppm at all times. Does this matter to the BBA?

For anyone interested in seeing me through this, I can provide more details as required.
 

Gerryd

Plant Guru Team
Lifetime Member
Sep 23, 2007
5,623
22
38
South Florida
Hi,

Without knowing exactly how much light/PAR you have....

I would GUESS the following if it were my tank which is about the same size.

1. No need for a 12 hr photoperiod. Reduce to 8 for now.
2. I would continue to dose macros/micros. You are supplying light and c02, why take the chance of a deficiency?
3. Manual removal is good. eliminate any heavily infested leaves.
4. I used a paintbrush (new) and dipped it into excel. I then brushed the areas that had BBA. Be careful not to let it drip onto other leaves/plants as it may kill them and cause some melting.
5. A spray bottle for the excel also works well for hard to reach areas.
6. Large water changes always help.
7. Over the course of time (3 yrs) if bio-mass has increased, then ferts and c02 also must be increased accordingly. Has this been done?

I would reduce the duration and amount of your lighting. Can you remove a bulb or two? Increase fert dosing, manual removalm etc,

Ensure the filters are clean as well.

Hope this helps.

BBA is USUALLY a sign of poor c02 but not always. Look to flow/current as well as plant mass and scape (rocks, wood) will affect current and flow.
 

Tom Barr

Founder
Staff member
Administrator
Jan 23, 2005
18,699
786
113
Yes, check the CO2 again and clean those filters!!!

I'd trim off any and all now, those old leaves are not worth anything to the plant, trim them.
They look bad anyway and have little place in a nice tank.

If you move ferns or anubias, the older leaves often get algae, if you trim just the worse ones, then wait a month or so, then trim a few more and so on......eventually you can remove them and have the new growth fill in, other folks just trim them all off and allow the new growth to come in after.
 

Paul G

Lifetime Charter Member
Lifetime Member
Sep 28, 2011
142
32
28
Independence MO
Thanks, Gerry.

Filters are OK. I check filters frequently and carefully. I use a lot of biomedia and am conscientious about clogging issues.

I have considerable vertical turnover circulation - about 2100 gph bottom to top, well dispersed horizontally using seven canisters. I also have six 100 gph "wavemakers" situated around the perimeter.

I can get a lux-meter and could report readings from that.

Of course, there has been plenty of plant growth over time. I routinely harvest great quantities of watersprite and hornwort. I had a vast forest of Java fern for a while until I thinned that out. I have been increasing the populations of Hygrophila, Rotalla, Nymphoides, and Anubias, mostly with success, especially as I began to dose ferts more liberally. Interestingly, I do not seem to be able to get my Echinodorus to thrive, but perhaps that's another thread.

Based on your comments, I should go to an 8 hour photoperiod, and I should dose iron and micros normally.

Regards, Paul G
 

Paul G

Lifetime Charter Member
Lifetime Member
Sep 28, 2011
142
32
28
Independence MO
Thanks, Tom.

Yes, I am cuitting off all those old, tatty Java fern leaves. Most of the larger tufts of BBA are on the wood.
 

Paul G

Lifetime Charter Member
Lifetime Member
Sep 28, 2011
142
32
28
Independence MO
Progress Report

I have been putting a lot of CO2 into this system and have kept the iron and micro delivery high. The BBA is under control. It has not disappeared entirely, but it is not spreading. Actually, I think it is gradually dying back. The overall impression of the system health with the CO2 injection running full out to keep the pH at 6.8 is very good. I am getting numerous inflorescences from the Anubia nana, and the Nymphoides are puttting up large floating leaves. Growth generally is excellent. Oxygen is 6 ppm when CO2 is running flat out (and barely holding the target pH, even with the reduced light).

Needless to say, I am very pleased with the progress being made. Thanks again to Tom, et al, for the enlightenment.

Regards, Paul G
 

Tom Barr

Founder
Staff member
Administrator
Jan 23, 2005
18,699
786
113
Remember after the grow in period, the CO2 consumption is often 1.5X or more what it was when you first planted things.

Trim those old ratty leaves, all of them!!!

Excel will keep BBA from getting too far along..but the CO2 by itself is the long term cure really.
Spot treating the non live stuff with H2O2/Excel etc when the pumps/filters are off will also kick the rest of the algae out the door.

O2 seems a little low, but if it's a canister system, then this is about right, you should hit 8ppm near the end of the light period.


Good growth and excellent O2 are two very good indicators that the issue was a CO2 problem.

I experienced this same thing in my 70 gal woodagumi with the HC, it stopped growing as nicely, never got algae or anything, but something was not right and not progressing as it should.
Since I have had many servings of Crow over the years, I knew to take my own advice.........add more CO2. the Erios which I always felt are the wimpier CO2 plants, was still doing well.
Ton's of light, tons of water changes, dosing, fresh ADA AS, cyled clean tank etc........not much is left except CO2.

So it happens to EVERYONE, but the more wise know it's a CO2 issue, even if they think it is not.
If you can confirm and rule out the other stuff....this narrows those choices down.

CO2 is rather tough to confirm and determine precisely what a general range is "good" for every tank.
My own tanks are 30ppm +/- and the lower end tanks have more light!

I have no real rational why that is.
 

Paul G

Lifetime Charter Member
Lifetime Member
Sep 28, 2011
142
32
28
Independence MO
Progress Report Follow-Up

For the last few days I have lengthened the photoperiod and have resumed the mid-day bright light. This made it hard for the CO2 diffusion to keep up (pH kept creeping up after lights on), so I installed an additional CO2 injector. That did the trick.

I am holding the pH at 6.78. CO2 is consistently 36 ppm. O2 starts the day at about 3.4 ppm but quickly goes to above 6 ppm for the rset of the morning, then to 7.4 after the bright lights have been on for an hour or so.

Questions:

There is no BBA on living leaves, including the Anubias. Live plants I assume produce algicidal allelopathy at their tissue boundaries (cuticle) which works if not overwhelmed. Or something like that?

BBA tufts appear on old leaves which are removed. Not so much on rocks, with just one tuft showing up on a lone pebble. Still quite a few tufts on the Mopani wood, but not getting worse (more numerous or larger). This situation is highly suggestive. Is it possible that organic components of the wood are a nutrient, or the slow decomposition of the wood is producing nutrient, that encourages BBA?

Apart from nutrients we expect to find because we are adding them intentionally, is it possible that DOCs recalcitrant to heterotrophic decomp are building up that are nutrient or cooperative inducement for Rhodophyta? Large water changes knock down any such concentration. Would implementing a higher level of chemical filtration have an effect? If so, I suspect it would be a long-term affair.

The rationale for why the salutary effect of CO2: vigorous plants produce high allelopathy; vigorous plants use available nutrient, if they are not CO2-limited or light-limited (out-compete algae). I don't doubt that this is the correct strategy. It is working. But I am interested in a comprehensive explanation with some technical details.

FYI, I created an album with some pictures of my 'scape.

Regards, Paul G