JimM

I've always had this very short fuzzy black algae appear on slow growing or older parts of plants in the past. Currently im fighting one of the most annoying cases of it that I have dealt with..

a little backstory, I received a generous donation of plants from a fellow forum member and it inspired me to tear down and rescape my tank that was in pretty bad shape (a failed project to propagate a full HC lawn with no other plants) I washed all the fluorite, bleached the tank and equipment then set it back up for my new plants.

specs:
29 gallon
110w GE Aquaray PC (10 hours)
pressurized co2 with a highly efficient inline diy reactor on eheim 2026 (tank is very well circulated, no deadspots)
Greg Ferts and lite EI + CSMB
hard water KH 15+

with the initial setup some of the cuttings I made struggle a bit, these are promptly coated with BBA.

every time i've read about this algae people suggest to up co2 to stop its spread.. well my poor rummy nose tetras looked like green brain glass fish stationary at the bottom of the tank hiding under a plant all day, jetting in random nonsensical directions if startled.. KH15+ PH reading about 6.8, I'd say I had plenty of co2. I moved the tetras into my 210 gallon so I'm left with only some cherry shrimp.. and upped the co2 even more today... pray for the shrimp..

the bba is even growing on my fluorite.. I spent the whole day looking for SAE with no success.

has anyone found that high co2 truly prevents its spread or growth? Ive noticed co2 has some effect, but the algae seems to be growing and spreading fine in my nigh seltzer water...

hoppycalif

The effect of high CO2 on fish is that it suffocates them. The only way a fish can get rid of it's own waste CO2 is for the CO2 concentration in the fish's blood to be higher than that in the water. So, as the CO2 in the water goes higher, the fish tend to gather at the top of the tank and gulp air from the surface. I haven't seen my fish stay at the bottom when I go too far with CO2. Your bad BBA attack usually means a too low CO2 concentration, so my guess is that it is too low, even though the KH/pH/CO2 tables say otherwise. Another test you can try is to take a tank sample of water, let it sit in the open air in a shallow container, for at least 12 hours. Measure the pH of that sample and compare it to the tank pH. A 1.0 difference is about as high as you should go, and that should be around 30 ppm CO2. If the difference is 0.7, the CO2 is only half of the 30, and if it is 1.3, the CO2 is about double the 30 ppm. This method cancels out any other source of alkalinity in the water besides the carbonates.

JimM

wow great timing, I just read your outstanding thread http://www.aquaticplantcentral.com/f...-to-try-4.html
and was about to give it a shot. I'll report back with my findings.
oh and good observation about the fish, they have never gasped, just lost color and their sense of direction when I turn up the co2.

houseofcards

has anyone found that high co2 truly prevents its spread or growth?
The short answer is that high co2 in itself is not enough to stop BBA. I run very high co2, my ph is around 6 and my kh hovers between 2 and 2.5, so that is alot of co2. Everyday after 4pm my tank pearls like crazy, bubbles everywhere. If I acclimate fish too quickly in the afternoon they go right to the surface gasping. The funny thing is I was getting BBA on some slow growing foreground plants that didn't receive good light and on some driftwood that did receive good light, but I was also getting it on the inside of my ceramic diffusor where I would thing Co2 concentration would be extremely high.

My unscientific conclusion was that the BBA grows where there is an imbalance of light, organics and/or co2.

erijnal

if you get to balance your tank, but want to get rid of the bba quickly, i suggest dipping your plants in a 20-30% solution of flourish excel for 10-20 seconds. your plants must be hardy, however, otherwise they'll die (for example cabomba will melt)

after that the bba will die off rather quickly and your balanced tank will keep it from coming back

Laith

Yes, I agree with this too. You can have high CO2 and still have BBA if you are deficient in some other nutrient.

Remember, the point of high (ie 30mg/l) of CO2 is not that the CO2 directly kills the BBA (it's not an algaecide!). But that healthy growing plants reduce the presence of algae. Take care of the plants and algae will be minimized.

Now don't ask me exactly how that works ! Lots of debate on that subject, including a good one here:

http://www.aquaticplantcentral.com/f...school-no.html

hoppycalif

I found that increasing the CO2 did not get rid of BBA at all unless it was just a few tufts of it. I have had to remove the infested leaves, clean the hardscape in bleach solution, and even dip some whole plants in bleach solution. But, the BBA only seems to return if the CO2 ppm drops for some reason. I certainly don't dispute that it is a good balance of all of the nutrients that is critical.

JimM

I think my problem here is not enough plant mass starting out. Nutrient levels are all where I want them, but there is some bare patches in the tank where I am farming some bba on substrate. The stargrass is exploding and there is not a hint of bba on it. its the stems that seem to not move much that are most affected (cuttings I made in hopes of new side shoots, etc)

I was thinking about the iffyness of the wpg rule and I am pretty sure that I have too much light, since the 29gallon has the same footprint as a 20g long, if that were the case I would be at like 6+wpg

Im just not really sure about what to do with the tufts of bba growing on my substrate, I removed as much as I could but im sure there is still some in there.

oh, after cranking up my co2 last night my PH dropped almost 2 full points between airated tank water and the tank.. from purple/red to yellow on my jungle 5in1 strips, tested multiple times. the shrimp and 2 otto were doing fine but I backed off a bit anyway.

erijnal

I know my original post in this thread was a little off-topic, but I felt I should update it in case anyone using the Search function finds this thread.

The 20-30% Excel solution had adverse effects on most of my Anubias barteri var. 'petite'. Granted, I wasn't really paying attention to the concentration of Excel since I thought any amount wouldn't hurt the practically plastic plants, but one to three leaves on each of my petites suffered complete tissue death on the leaves over time and the dying/dead leaves had to be chopped off.

The solution would still be a fool-proof way to get rid of GSA and BBA on your equipment though, it's just that with plants it's a little riskier.

redstrat

you also have to consider the accuracy of your testing methods for PH, test strips are notoriously inaccurate testing methods. A ph drop of 2 whole points would indicate some rediculously high concentrations of CO2, your fish would be hard pressed to survive in those conditions let alone stay near the bottom not gatherning near the surface gulping for air. I think your pH readings might be suspect and should be varified with another testing method. Regardless it seems, based on the discussion here, CO2 will not remove/kill BBA it will however help prevent it if your tank is in balance.