Laith

I posted on this problem at the beginning of the month and would like some new advice as problem hasn't improved much.

My 200l heavily planted tank is covered in what I call green "dust" algae following an increase in my lighting from 125W to 150W (added one tube). This stuff is very easy to remove from surfaces (its mainly visible on the glass) but within several hours is forming a new coating. I've tried several 50% water changes over a couple of days and it gets better for a day and then back to the same old...

GH=9, KH=9, pH 6.9-7.1, NO3=15, PO4=1.5, Fe=0.25, about 30mg/l of K added per week, CO2 (pressurized) injected and controlled with a pH controller. 2 tubes (50W) on for 10.5 hours, 4 tubes (100W) on for 9 hours (2tubes on before and after the rest).

I have considered removing the added lighting as this is what triggered the problem but would like to solve this otherwise. I mean this is only 2.8 wpg and many people don't have this problem with much more light...

Any brilliant ideas?

dennis

Well Laith,

Join the club. I have been having the same problem for about a month or so. Mine started when I got my CO2 tank filled and the needle valves and regulator did not want to adjust for some reason. Guess I was not tweeking htem the same or soemthing, I don't know. Anyway, I had CO2 about 5-10ppm for a few days in all my high light tanks and all this green dust appeared. At first I thought it was low NO3 making it stay so I tried upping my doseing to around 35ppm a week but that seems like it made it worse now. One thing I tried last week that seens to have helped is whenI change the water, I change about 80% or so, leaving enough water in the bottom for the fish and then I wipe the fuzz off the glass with a piece of filter pad. Clean small areas and rinse the pad out very frequently. Try to minimize the amount of water on your pad so that it doesn't just was the fuzz into the water. The idea is to remove it since green dust is (insert word I can't remember here) and it wil reattach itself in minutes to any surface.

I have not adjusted my NO3 levels since. I was planningon adjusting to about 20ppm NO3 and much less P (.5-1ppm) to try to slow down the uptake of N enough that it does not bottom out. It really seems that once you get this stuff that richer conditions fuel it, I know though that you can't starve algae. Excess may not cause algae but it is seeming for me that once you have algae, high nutrient levels allow it to proliferate.

The two tanks with the green dust are both 10 galons, one has 45watts and the other 30 watts, NO florescent. Both are heavily planted and the plants are growing very well in both tanks.

On a side note, and I don't know if this is a conincidense or not, but every time I dose Flourish, the algae really seems to..well, flourish. I dose 1ml every other day and on the off days thee does not appear to be much growth in the algae but when I dose in the morning, that evening when I get home from work, the dust seems to have increased by at least 50-75% . Maybe together we can beat this Sorry this doesn't help.

Edward

I would suspect excessive TE/Fe concentrations and keeping pH bellow 6.9 would also help.

Laith

hhhmmmm... low CO2? Interesting. My tap water here has just gone up from around 6KH to 10KH as it does usually at this time of year. So I raised the pH setting on the controller to avoid having too much CO2 in the tank...

And I've done the same, trying to feed more ferts to see if it helps. This may have led to too much TE/FE...

I like these inputs! Here's what I'll try: I'll set the pH controller down from 7 to 6.9 (so it'll fluctuate between 6.8 and 6.9). This will theoretically give me over 30mg/l CO2 all the time.

At the same time I'll do 50% water changes (after cleaning the glass) on a daily basis for several days.

Question is, should I stop dosing Plantex or just lower the dosages?

dennis

If you have a quick filter or diatom filter that would really help speed up the process. I have been considering getting one, but then I would not need it again for a very long time, if ever. I understand that the hagen quick filters are fine enough to trap green water so I would think one would trap these zoo spores. Interestingly, there was a topic about green dust in todays installment of APD. Tom BArr said basicall what we are thinking, CO2 up, scrup glass and water change. It should go away in a few weeks but mine has lasted longer, although the tank with it the longest is definatly not as bad as originally. I think I will increase my water change frequency aswell.

plantbrain

Excess traces do not cause this algae to grow in a high light tank.
That much I know.

I got a sample about 3 years ago and was intrerested in this algae, several other folks had it over the years.

I got to grow for about 4 weeks, fert's CO2, light wetc is seems to like once established.

It typically only grows on the glass or rocks.
If you wipte it off, the stuff reattaches(motile zoospores) within minutes.

So either filter it out, or wipe it off and toss the rag/paper towel etc.
I drain the tank a little, Scrub, then right away vacuum after letting some of it settle out.

This removes the little buggers.
I had trouble keeping it at high light/CO2/lots of nutrients etc.
I could never get it to come back.
Akinoscendemus is the genus.

I think folks are alramed by it since it reattaches and seems to grow right back, it's swimming around and landing back on there.
Not growing like mad, the amount of biomass is very very small, less than one med size crypt leaf.

It's got a fair narrow range of optimal conditions for it.

Messing with light, vacuuming, removing the biomass etc will get rid of it.
You might need to do a couple of scrubs and water changes, but that generally takes care of it.

Regards,
Tom Barr

dennis

I understand that what we/plants consider to be lean conditionsa e actually quite rich if you are an algae spore, so I understand that "excess" traces will not cause this algae. But why would not excess once you have the algae cause it to poliferate? It seems logical that once the algae hass settled on the glass, and you dose your traces, they wuold flow around and bang right into the settles spores at which point the spores go..holy crap, look at all this extra we have to eat!! If you say this is not right though, I'll believe you You said it has a very narrow range of optimum conditions; what are these conditions, knowing that would allow us to simple not meet those conditions? I assume low CO2/ high light but it also seems to be related to high NO3 levels also. I think in my case, I was pushing my tank to hard and now I have this.

Laith

So, along with multiple water changes, are we trying to reach a high CO2/high light, low NO3 situation? And keep other ferts up?

By the way, in my tank this stuff also grows on the plants, though less. I can rub it off the leaves in the same manner as the glass.

HeyPK

Try a few livebearers that browse on algae, such as guppies or mollies. Pond snails would probably also eat it up.

dennis

Paul,
Intersting you would say that. I have Rosy barbs in one of the tanks and it looked likethey were munching on it, so I did not feed them yesterday morning an dwhen I got home from work, they had cleaned quite a bit. Maybe 40% of what was on the front glass. I don't thing that fish are the answer to this algae, as only a few would touch it and it sems to multiply to fast.

Laith, definately this algae ssoms to come about with higher light and low CO2. I have heard that keeping lowered NO3 levels 10ppm, while battling the green dust, can help. I don't know. I dosed only 20ppm this week, instead of my normal 35ppm NO3 and htere was a definate improvement at the end of hte week. Of course, I did a more through job removing it last week and I've had it for a while so it might simply be that it has run its course.