Evil evil evil BGA

[QTOFFER]

I keep getting recurrent blue green algae infestations in my 29 gal. I've tried 4 day blackouts - they work, but the BG menace always comes back. Now it's taken over the 58 gal in the same room. Both tanks used to be lushly planted, but each successive infestation weakened the plants to the point that they're pretty unsalvageable. Both tanks have 1.2 WPG NO fluorescent lighting. There is no CO2 being added.

Fortunately, my 15 and 10 gal plant propogation tanks are unaffected. I'll have planty of Java fern and anarcharis to repopulate with. I plan to buy some anubias too. I noticed that my livingroom gets some direct sunlight for about 1/2 hour in the morning. I'm going to lower the blinds from now on. What's strange is that my bathroom actually gets more natural light than my livingroom, but the tank there is algae free.

Early this week, I pulled out what was left of the plants, vacd the gravel, scraped the glass, and did a 50% water change. I draped two heavy throws over each tank and taped them around the bottom so no light will be able to get in. (This is something that I did not do during the earlier blackouts.)

Since the tanks are now plantless, I plan to blackout for two weeks minimum. I've been feeding the fish at night in the dark by dropping some flake around the filter tubing. After the blackout is over, I'll do another big water change.

If this doesn't work, I'm gonna throw a mixture of bleach, ammonia, battery acid, dioxin, and radioactive waste into the tank!!!!!

I'll update in a week!

 

[7Enigma]

How heavily stocked is your tank? BGA is generally caused by low nitrAtes (from low bioload compared to plant mass), and generally found in stagnant or low flow areas. The fact that you have relatively low light levels would lend me to believe its more a low flow issue than a nitrAte deficiency...

EDIT:
"8 tiger barbs(Puntius tetrazona)
6 brilliant rasboras"

I see you have about 14 fish in there. That should be an adequate load to more than cover the nitrAte issue. And your filtration (Fluval) should also be adequate, but check for low flow areas in the tank.

Calcium sulfate is a great safe "flow tester" as it is a very fine powder that is not particularly dense when powdered and dissolves very slowly. You can put it in the tank and watch for areas that don't get much turbulence and then add a PH or move the output/inputs to get more even flow.

Do you have access to a diatom filter? It's possible you have a lot of dissolved organics in the water that are ripe for scum to grow. A thourough diatom filtering (including kicking up the substrate) with a heavy PWC after might help.

Otherwise I have no answer to how to fix or what is causing it...goodluck.

 

[QTOFFER]

Thanks for the reply, 7Enigma.

The nitrates in both tanks bottomed out to 0 about a year ago when I was having trouble with green water. I seem to have solved that problem by doing water changes every two weeks instead of weekly. I always deep gravel vac (BN plecos generate lots of poop) and use the diatom filter about once a month.

The current in the 58 gal is great judging from how flake food moves around during feeding time.

However, the current generated by the Fluval in the 29 gal produces several dead spots. I think it's because the fluval doesn't have a spraybar. I've been thinking of adding a PH with a spraybar that would sweep across the gravel surface (where the BGA tends to accumulate most). I want this to be an East Asian tank, and I think hillstream loaches would probably enjoy the extra current.

Once this BGA issue is solved once and for all, I plan to completely rescape both tanks and do some serious restocking in the 29 gal.

 

[jersysman]

I would say that since your nitrates are bottoming out, you would need to get some nitrogen into your tank. Your plants are probably using it up and the nitrogen/phosphate ratio is probably out of whack. You could start dosing your tank with Flourish Nitrogen to get that nitrate level back where it should be.

 

[QTOFFER]

I unwrapped the tanks today after two weeks of blackout.

All traces of BGA.....gone!!!!

Question is, where did it go? Two weeks ago, my rockwork and driftwood were completely covered by Jolly Green Giant puke. Now they are clean and the water is crystal clear.

An even bigger mystery is why my poor pathetic anubias doubled in size and sprouted six new leaves during the blackout! 8O

Fish look great. I had been feeding every other day at night through the filter opening on the hood. I did a 50% water change, but I forgot to check the params - dang. Tomorrow I'll check the water params and do some maintenance on the filters.

 

[rich311k]

Congrats, I love stories about dead BGA.

 

[MyCatsDrool]

IMHO you are right at that "weird planted tank light threshhold" where you are going to be hit and miss with algae. I am still pretty green (no pun intended) on planted tanks, but you might consider dosing a small amount of CO2 when you replant...myabe 2 2liters of DIY through a powerhead...and some ferts...maybe a comprehensive like flourish with added nitrogen. Perhaps even skip the DIY CO2 and go with Flourish excel dosing.

Again, i am a newb, but i think it might help. 1.2 is right at that threshhold.

 

[joannde]

QT - I feel your pain ! My nitrates bottomed out once in my 10G while it was a divided betta tank. Since then its been broken down, cleaned and redone. This time I was careful to dose nitrates but the ^#Q&$@ BGA came back anyway !
I managed to keep it under control (to some degree) by removing the visible portions (along with 1 - 2 gallons of water) daily via turkey baster. Then I started to neglect the tank and the fish (my dog was dying of cancer) - and the BGA got BETTER !
I do think that dissolved organics play a role in BGA so I'll be using carbon in that tank going forward - I'm assuming the fzn bloodworms add alot of dissolved organics in the water.
.... a 2 wk blackout .... man, I hope it doesn't come to that ! I'm finishing up a 4 day blackout today that I was hoping would kill whatever BGA remained .... now I'm scared of the Jolly Green Giant Evil BGA Puke again ! LOL

 

[Purrbox]

I'd say that the Nitrate bottoming out was probably the primary cause of your problems. At a guess I'd say that your tank is probably fairly heavily planted and lightly stocked, so the fish aren't producing enough waste to keep up with the rate the plants are consuming the nutrients. Shouldn't need to worry about CO2, but it's probably worth it to pick up some ferts and start doing some dosing to ensure that your levels stay up.