Cyanobacteria issue

[TXaggie]

So about a week after putting my new light on my 29g tank I've got BGA growing on the moss that is closest to the light in the tank. : ( I'm pretty confident in what it is, as it's bright blue green and slimy looking.

Seems like my best bet according to what I'm reading here is to do an erythromycin treatment after trimming or removing all the stuff I can see on the moss. I've already reduced my photoperiod to two four hour chunks split by a dark period during the middle of the day.

I was already planning on taking my tank apart to do a new substrate and replant/rescape next weekend. What do I need to do to keep the problem from coming back? I change 10-20% of my water weekly, dose Flourish twice weekly (based on advice from AA that my plants were showing signs of nitrogen deficiency, which has since improved), and do root tabs monthly. I'm changing out my gravel for Eco-complete plant substrate. My filter is an AC 70 so I feel like I have plenty of flow in my tank. Do I need more plants? Less ferts? More ferts? Ugh, I really don't want to end up with a constant algae (bacteria really i guess) battle just because I improved my lighting from super low to low medium.....

 

[Berylla]

What is your new light? What bulb? I had some cynobacteria when I first put some new moss in my tank. I took out my moss, and sprayed with hydrogen peroxide and let it soak for 15 minutes, rinsed in dechlor water then dumped back in my tank.

 

[TXaggie]

I've got the FugeRay 30" light, should be med/low lighting in my standard 29 gallon. That said, the moss with the slime is closest to the light of anything in the tank.

Would it be worthwhile to try just removing the moss with the issue and treating it?

I guess I'm confused because I've read that BGA is caused by low nitrates, or by high nitrates. Not sure how both are possible or if that means I should change my fert frequency?

 

[aqua_chem]

Cyanobacteria is one of those things that has a number of circumstances that will almost definitely cause it, but it also sometimes just happens.

Things that have been observed or suggested to cause it: No nitrates, low nitrates, too much light, poor tank maintenance, insufficient flow, etc. And sometimes it just happens. If it comes back again, you know it wasn't a random case.

 

[ashleynicole]

I haven't had BGA in years but when I did, a blackout for 3 days took care of it. No need for antibiotics.

 

[Berylla]

I would remove moss and spot treat. I don't like using medications unless necessary and only in a QT tank.

 

[TXaggie]

Thank you for all the advice! I'll start with just removing the affected moss and spot treating. I guess I'll just have to wait and see after I rescape if it becomes an issue again!

So glad I have this forum to come too when I have questions.

 

[aqua_chem]

I've tried blackout and H2O2 spot dosing. Neither were very effective, while antibiotics kills it dead every time. It probably has to do with the severity of the infestation, and the conditions of the tank. If you're going to try to avoid antibiotics, I would try:

1) Physically remove everything that you can.
2) Spot dose with H2O2 on effected areas.
3) Blackout 3 days
4) Spot dose daily (or twice daily) during blackout with minimal light

 

[TXaggie]

Thanks, aquachem. I did what ya'll recommended, trimmed out as much as I could and spot treated with H2O2 the BGA and some hairy looking white algae. Did a ~ 40% water change and I'm going to black out the tank for the next three day. Hopefully after the rescape I'm doing on Sat I won't have that problem recur.

Before treatment today and after:

 

[Berylla]

Nice tank! I like your placement of the moss.