Blue green algae

[Vallisneria]

A friend of mine is in the process of fishless cycling(been a bit over 4 weeks now) their tank and it now has blue green algae taking over it. They have plants in the tank and now this blue green algae is starting to cover everything, the plants, the decorations and the gravel.

So what should I tell them to do? This is their first tank and I've never really delt with cyanobacteria before, besides in one tank that I ended up tearing down and bleaching because of it.

Here is a bit of info about their tank

38g

moderately planted(crypts, java fern, vals, dwarf sag)

Sil #9 gravel

temp 80*

xp1 for filtration

around 2watt/gal

Its been fishless cycling for about 4-5 weeks and is pretty much done but they live in fort mac so they have to wait until they come into edmonton to pick up fish for it. So its currently doesn't have any fish. He did do a water change about 2 weeks ago as they thought they might be getting fish but ended up not coming into town. So since then he has just been adding ammonia daily to keep the cycle going. Not sure on his exact test results but it sounds like the tank is cycled and just in a "holding pattern" until they can come get fish.

Do they treat with erythromycin? Will that kill their beneficial bacteria? Please help as I have no clue and they want to clear this up so they can get fish maybe by this weekend or next.

[jvision]

A 4 day blackout will do the trick. Are they adding ferts? If so, have them do a 50% WC and dose extra KNO3, then black out completely for 4 days (but keep the cycle going), then on day 40, do another 50% WC and dose normally.

I am not a fan of medicating tanks when not needed.

[Vallisneria]

Does it matter about medicating since there are no fish in the tank and it will be receiving a 100% water change before it gets any fish? Does the medication affect the plants or kill the bacteria?

They don't have any ferts for the tank yet. I was going to give them some when they came into town. But I can tell them to do a black out for 4 days. There is lots of Nitrates in the tank already since its been fishless cycling for so long, so I dont' think lack of nitrates is causing the algae.

With a blackout will the BGA just come back once the tank starts getting light again? Or is a 4 day blackout enough to kill it so it won't come back.

[jvision]

The BGA may come back one more time after the black out, but I've never seen it come back strong. I don't remember if Erythromyacin will affect the biofilter or not - make sure to read the package BEFORE purchasing to make sure. Again, I really don't think there's a need to medicate, but it's their tank...

[geleen]

I was reading this in a seachem article written by

Gregory Morin, Ph.D. ~~~~~~~Research Director~

"By cyano I assume you mean the blue-green "algae"? According to Baensch Atlas

volume 2 pg 162, the blue-green algae aka cyanobacteria can flourish

in the following conditions: strong sunlight, rotting substrate,

excess feed, too few water changes, overfertilization or _high

nitrate levels_"

So this is what you mean Jason? Just to wrap my mind around it. I know, I know, it takes a while The tank likely has very high nitrates and a lot of light: causing BGA

A large WC and blackout should then take care of it.

Edited February 24, 2010 by geleen

[jvision]

Super high Nitrate levels are often a culprate in fish-only or lightly planted tanks. Myself and others have also found that low/no nitrate also contributes (probably due to plants unable to outcompete), which is why I said that if they were fertilizing, they should add a little extra KNO3.

[geleen]

Ok Thanks

But wouldn't it be possible that a cycling tank goes very high in nitrates? and with the lights on causes the same problem?

John

[Vallisneria]

Ok Thanks

But wouldn't it be possible that a cycling tank goes very high in nitrates? and with the lights on causes the same problem?

John

Yes they have super high nitrates right now because of the fishless cycle.

I called them last night and told them to do a blackout for 4 days and then do a water change and try to suck out/clean out as much of the dead algae as they can. If that doesn't work then they will go to step 2, the antibiotics.

Thanks :beer:

[jvision]

I'd have them do a big WC BEFORE the black out and suck as much out as possible. There won't be much, if any algae left after the blackout.

[algae farmer]

At 2 w/gal of light without CO2, they are approaching a fine line of trying to balance the tank. I would suggest that they cut their light down to 1w/gal after they do their blackout proceedure as jvision suggested. I myself haven't had much luck in using ammonia. The few times that I experimented with it I always had algae issues. Use ferts. sparingly in any new setup. Once the plants are acclimated and have started to establish themselves (4 weeks) they can SLOWLY increase the ferts. Since they are new to the hobby the biggest hurdle the will have to overcome is to be patient.

Also advise them to stock their tank lightly with fish at the start.

take care

PS

[Vallisneria]

OK I'll call them later and tell them to do a big water change today to remove as much algae as possible and then again at the end of 4 days.

The plants have been in there about 2-3 weeks now and they were planning on adding DIY co2 soon or maybe excel instead. They were just waiting to let the plants settle in a bit before adding co2 and ferts. Also with the high ammonia,nitrite and nitrate levels during the fishless cycling process they thought it would be enough plant food and they wouldn't have to start adding ferts yet.

[Vallisneria]

OK little update, still having problems...

My friend called me today and said they are still having problems with the BGA. They did the 4 day black out last month and it helped but didn't get rid of the algea and its back just as bad. They are having to clean it off the plants/rocks and glass every few days or it takes over everything.

So what should they do? I told her to clean off as much as they can and do another black out for 4 more days. But that obviously didn't get rid of it the first time and they are worried it will just come back again. Could they do multiple black outs? 4 day black out/ 1 week light/ 4 day black out etc? Would that make a difference or would it hurt the plants too much?

They increased the lighting a bit. They now have 2x39w HOT5s over the tank(its a 40g) and have a 4l DIY co2 jug going. She said half the plants(java fern and crypts) are doing well and growing but the other plants(vals, dwarf sag) aren't, they are the ones covered in BGA.

So what should I tell her? More black outs or is it time to try the erythromyacin treatment? Is there a fert imbalance that would be causing it?

[Shai]

BGA also does not like current. How strong is the water movement in the tank?

[Vallisneria]

They have an XP1 on the tank. I had already asked them about current and they said that there is a fair amount in the tank. All the plants are swaying in the current and they say there isn't any dead spots.

The BGA is all over their tank. Not just in certain areas.

[Kronosdelsol]

This is my suggestion. If they still have those plants you mentioned in post #1 then I would, do the 4 day black out again, then take out one bulb and only have the other bulb on for 6 hrs a day. If there is direct sunlight hitting the tank then only turn the light on for 3-4 hrs. Stop using co2 entirely. Those are all low light plants and don't really need injected co2 (assuming there is fish in there now). Don't fertilize for the next two weeks, then check the levels and slowly fertilize one only (e.g., kno3) and see how that reacts. The most important thing is to tell them to make small changes slowly. They need to learn how the environment reacts.

I would throw in some fast growing plants to suck up the excess nutrients. Maybe hornwort or watersprite.