# Black Spot Algae?



## OldManShiver (Mar 30, 2004)

Overall my tank is doing very well. The only unsightly part of it is, for lack of a better description, the black spot algae that grows on the leaves of the slower-growing, broad leaved plants (Echinodorus, Anubias). It appears on the older leaves, so it's a slow growing algae. I tried searching the forums and didn't find anything that sounds like what I have. Anyone have any idea what I'm talking about? There is no other algae in the tank. It definitely isn't BBA...I did my time with that stuff! 

I have a 75 gallon with about 4 WPG of light, CO2 in at about 2 BPS, ferts I guess would be considered EI methodology, though I change about 40% every 2 weeks instead of weekly. Substrate is 4" of laterite enriched sand/gravel with a 1" peat base. Temp about 77-ish, pH is around 6.6, KH about 3 or 4, GH in the 5-7 range.


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## trenac (Jul 16, 2004)

Sounds like Green Spot algae to me, it may appear to be black. This is usually brought on by a lack of phosphates. Also make sure that your C02 is at 30ppm with that much light. If you are going to use the EI method then you need to make the weekly 50% water changes required for this method.


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## stcyrwm (Apr 20, 2005)

trenac said:


> If you are going to use the EI method then you need to make the weekly 50% water changes required for this method.


Trenac,

Tom says it's okay to not do the 50% weekly changes - it is just that you have to adjust your dosing regime accordingly if you don't. The 50% change guarantees that you are never over twice the amount you are dosing and so helps with the "estimative" part of the equation.

Bill


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## hoppycalif (Apr 7, 2005)

EI is not a great "mix and match" system. If we take only parts of it, then mix in parts of another method, we really are asking for troubles. While it is true that you don't absolutely need to do 50% water changes weekly, you should do big water changes almost weekly, even if those are 33% or 66% changes. Similarly, if we are dosing a half tsp of nitrates every other day, we need to be dosing about 1/8 tsp or more of phosphates every other day too. If we were to be sure we have enough CO2 (use a drop checker), use only as much light as we need, and dose per EI, we should be able to keep any algae problems under control, so why not just do all of that? (My excuse is that I tend to be too lazy, but I don't present myself as a role model.)


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## steelhead004 (Mar 4, 2007)

Graham said:


> Overall my tank is doing very well. The only unsightly part of it is, for lack of a better description, the black spot algae that grows on the leaves of the slower-growing, broad leaved plants (Echinodorus, Anubias). It appears on the older leaves, so it's a slow growing algae. I tried searching the forums and didn't find anything that sounds like what I have. Anyone have any idea what I'm talking about? There is no other algae in the tank. It definitely isn't BBA...I did my time with that stuff!
> 
> I have a 75 gallon with about 4 WPG of light, CO2 in at about 2 BPS, ferts I guess would be considered EI methodology, though I change about 40% every 2 weeks instead of weekly. Substrate is 4" of laterite enriched sand/gravel with a 1" peat base. Temp about 77-ish, pH is around 6.6, KH about 3 or 4, GH in the 5-7 range.


Try 2/3rd's water changes ... It should be plenty. Try less peat!


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## OldManShiver (Mar 30, 2004)

Thanks for the input everyone.

I'm getting the drop checker online soon, so I'll see where that's at. The odd thing is that one of the plants (Tropica sword) with the spot algae pearls all day. My understanding is that this means there is "excess" metabolism happening and all the raw materials needed are present. I do know that I tend to go a little light on the PO4, though so I'll try to keep on it better.

I also know that more water changes wouldn't hurt anything, but I also have that problem of not enough hours in a day... 

As for the peat, it's too late to use less!


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## erijnal (Apr 5, 2006)

Anyone figure out a way to get rid of this?

I have a lot of it on the older leaves of my Anubias barteri var. 'Petite'. It isn't a spot algae, really, as it eventually turns into a larger mass. It's more like the diatom algae, but a much darker color, and this is in an established tank.

Also, unlike GSA, this algae appears to survive Excel dips.


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## hoppycalif (Apr 7, 2005)

CO2, as important as it is, is almost worthless without enough water circulation to get a steady supply of CO2 enriched water to all of the plants. That is possibly an overstatement, but not by much. I have repeatedly found that my algae problem increase in proportion to how crowded my tank is with plants. The more crowded, the less water circulation I get within the heaviest planted areas. But, the drop checker always says I have 30 ppm of CO2. We just need to keep up with water circulation just as we keep up with other tank parameters. That generally means pruning regularly.


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## erijnal (Apr 5, 2006)

hoppy, I've upgraded to pressurized and I've got good circulation in my 10 gallon tank with a filter/pump combo. So far, I've gotten no black spot algae on any of my new anubias leaves, but they're still hanging tough on my older ones.

The thing I'd be interested in most is how to get rid of existing BSA. After pruning some anubias leaves, I tried rubbing/scraping it off to no avail. The time I'd have to wait for 5-7 leaves to grow back after pruning for each petite I have would suuuck


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## hoppycalif (Apr 7, 2005)

Anubias can grow pretty fast when they get good fertilizing, CO2 and good light. So, it might not take as long as you expect to replace pruned off leaves. You could just ignore the bad leaves until you get more good ones, then prune them.


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