Stupid annoying BGA

[QTOFFER]

I've really had it! A month after a four day blackout, two of my tanks (the 29 and 15 gal) had an explosive outbreak of stinky, blackish green BGA. Why does this stuff keep coming back? No new plants or livestock have been added for weeks. I blacked out again for six days and did a 50% water change followed by an hour with the diatom filter.

I had a beautiful piece of driftwood in the 15 gal that used to be covered with small leaf Java fern. The BGA completely covered it and smothered everything. There's still some Java fern at the ends - hopefully it will grow back.

Ammonia=0
nitrite = 0
nitrate = 5
phosphate = 2
Light = 1 - 1.2 WPG for 8 hours/day, no CO2, no sunlight
I dose with potassium twice a week
I dose with Flourish once a week
I do 50% water changes once a week



My 58 gal was blacked out for BGA a few weeks ago. Now I have green hair algae everywhere (driftwood, plants, glass, substrate), and some BBA on the plants. Parameters and dosing same as above, except light = 1.8 WPG. I've been pruning off leaves that have BBA.

I'm thinking of discontinuing the Flourish - maybe too much micronutrients are encouraging unwanted growth.

I've cut my lighting interval to 6 hours/day - down from 8.

I'm also thinking of cutting my weekly changes to 25%. My tap water has 2ppm phosphate, and my big water changes are probably preventing nitrates from ever going above 5. I know that the P/N ratio should be 1:10

Any other suggestions? BTW, the fish in the affected tanks look fantastic - too bad their surroundings look like green crap!


P.S. Is the LaMotte phosphate test kit worth the money? I have my doubts about the accuracy of the AP test.

 

[Hoovercat]

Feel free to doubt the accuracy of both the AP NO3 and PO4 tests. After doing so, DOSE your tank up to the recommended 10/1/10 levels after a 50% water change using EI only. Forget your test readings. BGA often occurs when NO3 bottoms out and 5 on the AP test may well be 0. Keep all your macros available by dosing with EI (full levels beginning, then 1/4 mid-week, then 50% water change at end week, followed by dosing half levels). AP kits are fine for seeing if anything is getting dangerously high but are sad at accurate low level readings. Take your lighting back to 12/12 if you don't plan to do another black out.

 

[rich311k]

I am with Hoover. I took some advice from folks around here. I dose 10 and 1 and 10 every other day. Micros and iron on alternate days. My algae is just about gone. What is left comes off with just a wipe of my fingers.

 

[caribou]

I bought the LaMotte high range kit and would say it was really worth the extra money. I've tested it against my well (tap) water and it is right on the mark. I know the parameters of my well water because I have it tested twice a year. If you can't trust your test kit, you never really know where you're at. I agree with cat and rich, you probably need to up your NO3 and balance it with K. Check out the stickies at the begining of this forum. Good Luck!