green spot algae

john b.

Junior Poster
May 21, 2005
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I've been using the EI for a few months now and everything is going very well. The only problem I have is green spot algae on the glass of my tank. I am dosing the following to my 55 gal.,pressurized co2 to about 40+ ppm, 4+ wpg tank:1/2 tsp. kno3, 1/8 tsp.k2so4,1/8 tsp.kh2po4 every other day and 10-15 mls.csm+b on off days.I tested the water right before the weekly 50-65% water change and my phosphates seem rather high, 5ppm or higher.Also nitrates at the end of the week are about 30-40ppm. I tested my po4 and nitrate kits with a few standard solutions and they seem ok.I have a low fish load and don't overfeed either. Water out of the tap has no detectable no3 or po4.My kh is 3 deg. and gh I raise to about 7-9 deg. using calcium chloride and epsom salts. I'm not sure what to do about the gs algae as most people say raising po4 gets rid of it.Any advice would be appreciated. Thanks,
John
 

Tom Barr

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Jan 23, 2005
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Re: green spot algae

If you have enough CO2, go ahead and add a tad more.
That's the only thing that would encourage GS.

If you are adding that much PO4, we can rule that out even without a test kit.

What about plant biomass?
It there a lot of plant biomass?

If so that leads right back to CO2.
Critical testing of CO2 typically has an error of at least 5ppm.
Also, testing with a pH probe with electrical equipment like lights etc will give a false positive.

Just add a tad more CO2 and watch the tank.
You do not need the K2SO4 BTW. More than enough K+ comes from the KNO3 alone. You can lower the GH to 5.

Try flourish or TMG instead of CMS+B.
Add 10mls 3x a week.

Try this and see.
I hate green spot more than any algae personally but I do not have issues with it unless the CO2 or the PO4 is allowed to drop or a combo of both.

Regards,
Tom Barr
 

john b.

Junior Poster
May 21, 2005
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Re: green spot algae

I'll try upping co2 levels, right now I have a ph of 6.3 and kh 3 deg. which I thought should be plenty of co2. Also the tank is heavily planted. I'll try more co2 and see the results. thanks,
John
 

john b.

Junior Poster
May 21, 2005
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Re: green spot algae

it's usually recommended to have a kh of at least 3 deg. with co2 injection.
 

Tom Barr

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Re: green spot algae

I've gone to 1-2 KH ranges without issue, but if you are light on CO2, the plants will go after the KH, so it's nice to have some for them just in case.

FYI, you can have a tank and use CO2 with a KH of 0.
You measure it indirectly at a KH of 1 or 2 and then remove the KH via DI/RO water change and maintain the same CO2 bubble rate you had with the higher KH.

Plants will do well still.
They want CO2, not KH if there is enough CO2.

The pH issue really does not hurt the fish.

Don't try this unless you are willing to kill things, get algae etc.

Regards,
Tom Barr
 

john b.

Junior Poster
May 21, 2005
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1
Re: green spot algae

I just wanted to give an update on the gs algae. After raising co2 levels and changing to flourish, there is no gs on glass so far when usually the whole front glass would be covered by now. I have a little green dust algae but I'll take care of that with the wiping technique :D. It seems as though the co2 was the issue, though I don't want to make a rush to judgement.Anyway, thanks Tom,
John
 

Tom Barr

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Jan 23, 2005
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Re: green spot algae

My rec's almost always target better plant growth, so no matter what, there is a tank improvement.

Regards,
Tom Barr