Erythromyicin treatment for cyanobacteria (BGA)- yes or no?

[fort384]

Well, as I have mentioned, I have a little bit of BGA growing in my tank. It has been there for several weeks, but since adding a bit of extra light to my tank last week, my plants are growing faster and look healthier, but I have also noticed the BGA tends to come back quicker too. It is not out of control - I usually spend 1 or 2 minutes every other evening just to touch up/remove whatever has grown with a small brush.

I am pretty sure it is BGA - very slimy, dark green with a slight blue tint, grows mostly on the substrate but a bit here and there on the java moss/ferns.

My question is this: Should I continue to just do regular maintenance/removal and except this small nuisance as a cost of business for fertilizing/high-ish light conditions, or should I consider treatment with erythromyicin?

There seem to be conflicting viewpoints out on the WWW regarding how much if at all treatment will effect my biological filter. There is also concern about developing antibiotic resistant BGA. The one thing there does seem to be agreement about is treatment with erythromyicin will eradicate cyanobacteria.

 

[jsoong]

I vote no.

The BGA is under control with normal maintainance. You can prob. get total control with simple measures such as increasing water circulation.

Erythromycin can disrupt your filter bacteria & other fauna in the tank. Upsetting the tank's balance might make things worse.

Even if you eradicate all the BGA, it will come back if condition is right.

So I think erythromycin should be reserved for when the BGA is out of control, as a means of temporary erradication while you fix the underlying issues that cause the BGA in the first place.

 

[Purrbox]

Erythromyicin should be the treatment of last resort. Make sure that your Nitrates aren't bottoming out and that you have good flow in the areas where the BGA is growing.

 

[fort384]

Nitrates are at 10-20 ppm. How would you suggest I increase flow? I would say there is not much flow on the surface of the substrate where most of the BGA is accumulating. I have tried vacuuming it up but it keeps coming back. As I said I do manual removal every other day or so, but I feel like I am just spreading most of it around, not hauling it out of the tank. Again, talking fairly small quantities here, just borderline nuisance. If it were just some plain ol algae I wouldnt be as concerned, but there is nothing healthy about a bacteria "infection" from what I can tell. Not to mention it is very unsightly, even in limited/small quantities.

---OFF TOPIC---
I gotta say though, thanks to all of your great advice, my tank is looking great. Lots of pearling, and my plants all seem to be growing like crazy. BBA is all but gone, and lots of new plant growth. If I could just nip the BGA in the butt I would say my tank would be close to perfect at the moment. Even saw my first MTS last night... but don't see him anywhere today. I think my zebra loach was probably happy to see him too. AGain, thank you all for the help!

I also decided today that my short-lived days of mixing yeast and sugar are over - I ordered the Milwaukee MA957 regulator/needle valve/bubble counter/selenoid today. Looking forward to its arrival.

 

[czcz]

I realize that there's a lot of different stuff that goes by Cyano, but let me share an idea: in layered substrates (for example, peat pumice then soil) one will often see Cyano near the bottom of the substrate, where water is obviously trapped and (good) anaerobic bacteria lives. (Some may remember the pics, but I was worried about this Cyano on my DIY "Powersand" / Aquasoil tank until more than one Guru and a couple friends told me they get it on deep layered substrate too, they just crop or don't take pics showing the substrate on the high slopes .) Whatever type of Cyano this is seems to go away or at least be somewhere between ignorable and invisible once plant roots penetrate into the lower layers.

I have some in my current tank inches above the substrate line where sunlight hits but interestingly it is dying back without adjusting flow but while the plants ajacent grew thicker and more readily pearl.

So, what if it's not filter flow but rather high oxygen that keeps BGA back? What if we attribute high nitrates as a Cyano deterent in the planted tank because tanks near the optimum nitrate saturation (per Plantbrain N articles from a few years ago, from memory, this is 20-60ppm NO3?) have faster growth (more plant mass in x time all else being equal).

If the plants are now adjusting and pearling and look nice and healthy, and some of those pearling plants are at the substrate line and easily pruned should BGA spread on them, maybe let this bacteria be for a week, assuming it is not spreading quickly. You may be surprised.

 

[fort384]

Interesting. Would you suggest then that I also increase no3 to that level? I am currently keeping them around 10-20 ppm. My only concern with the method you suggest: the only plant I would say it is negatively impacting is the riccia I have tied down on a rock at the bottom. It is really difficult to clean it off without ripping apart the riccia, and I am afraid if I let it go a week, it may choke the riccia off/make it impossible to clean.

 

[fort384]

Well, unfortunately, I would say it is getting much worse. I didn't touch it for 3 days, and I would say it is now covering about 1/3 of the substrate and it is making its way up my rotala. It is getting frustrating. Water tests are saying I have the right mix of macros, and the plants look good. The sick part is, the cyanobacteria on the bottom is so healthy, IT is starting to pearl...

 

[czcz]

I'm not sure my idea has any merit and I'm wondering what folks think, and I think it'd be great if you tried it, but if yours was my tank I probably wouldn't change a thing. If you're able to reach O2 saturation from plants (pearling) and assuming you're not say injecting pure O2 into your tank or using a wet/dry or something, you've probably reached that great moment for a young tank of enough plants and good execution of a good dosing method where all you should care about is growing more plants (propagation). So, if it were my tank, I'd enjoy happy Riccia for a while until I had enough to make a second rock, and when it was time to trim I'd have that rock and a good spot ready for it. If manually removing BGA still hasn't defeated BGA, then I'd suggest giving the idea above a shot. FWIW, of course.

 

[fort384]

Well, I am going to try reducing the light cycle a bit, from 12 hrs to ~10.5. I also dosed some extra N and P tonight, will see if that helps, or makes it worse.

I really think when my CO2 regulator gets here and I can really consistently keep CO2 at optimum level, that will help substantially. But what the heck do I know?

 

[czcz]

Just read your last post. Tasty beverage makes slow typing.

For clarity on your maintaining 10-20ppm NO3: if I understand correctly that you're dosing to maintain targets, this means you are dosing to 20ppm NO3, then after a few days or tests you're around 10ppm NO3 and so you add 10ppm more, yeah? If its all fish/organic waste (no dosing you just measure these levels), you still keep your method if you dose to the upper level of your ranges: there's good evidence that plants can more easily break down and uptake inorganic NO3+ than organic NO3+.

I have lots of thoughts about Nitrogen that can go into another post if folks care, but really the gist of it is we should all notice that one of the things every proven method has in common is N addition when there is CO2 addition. In your method this is probably what the upper ranges are for.

 

[fort384]

Yes, that's about right. I have been dosing N twice a week. It tests out at about 20ppm a day after dosing, and about 10 ppm right before dosing again. I am going to try and bump that up to 30 ppm after dosing, and 20 ppm right before doing and see if that makes a difference. I put the CO2 into overdrive today too, got the DIY system cranking at about 2-3 bbs. From what I have read, the BGA does not appreciate the high levels of CO2, and the lower pH that it brings.

 

[czcz]

That's interesting -- I have not heard this idea but it makes sense that a bacteria would find it difficult to adapt to a sudden swing in some parameter. I wonder if, say, a rapid change in temperature would work?

(Without animals of course.)

 

[fort384]

Not sure if I could make that work with all the shrimp and everything. Would be very difficult for me to isolate all the fauna in my tank. I was just thinking about T though, funny that you brought that up. I would say my tank is on the high end, stays right at 80 degrees F. Not sure how I could lower it short of a chiller - the heater rarely if ever kicks on. But it does seem to me that the higher the temperature (to a point of course), the more a bacteria would thrive. Not sure though that the temperature swings that my animals could tolerate would have any kind of effect on bacteria. It may slow it down a bit if I could get the tank to 75 or 76, but I don't think it would be an effective method of eradication.

 

[czcz]

Yeah, I was thinking of easier to remove animals and dumping in a full tray (or two? Thats probably a bad idea...) of icecubes.

 

[fort384]

Well, after weighing all the positive and negatives, I decided to treat with erythromyicin. Started treatment yesterday. Cleaned all BGA out of the tank, and installed a variable direction power head. So far so good. No new growth of BGA today, which is a first, and ammonia levels have not become measureable in the last 24 hours. Will continue to monitor, and let everyone know how it goes. I am hoping the increased flow, coupled with my new CO2 injection system, will keep it at bay.

 

[Puddle]

Hi there,

For all its worth, I used to have BGA really bad and just did a 3-4 day blackout and not had it since, as long as nitrates are not bottoming out seems to be an easy cure....

 

[fort384]

Well all, I figured I would give you an update. The erythromyicin treatment worked wonders. I stopped the treatment after 5 days, and have not had any signs of the bacteria returning. Hopefully the CO2 injection and the powerhead will keep it gone. Also, I had no noticeable trace of ammonia or nitrites during or after the treatment.