# 8g tank new algae, will co2 kill it or make it grow?



## customdrumfinishes (Apr 4, 2008)

i have a 8gtank and have high light on iti have just got some small spots of green algae, pinhead spots. im guessing to much light, i want to put a diy co2 on it but not sure if it will make the algae grow or die off.i have shimp in this tank so i dont want to kill them lol


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## BiscuitSlayer (Apr 1, 2005)

Light green = GDA (green dust algae). CO2 will hinder its growth.

Dark green = GSA (green spot algae). CO2 will have little impact, but dosing phosphate will.


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## customdrumfinishes (Apr 4, 2008)

ok thanks, its dark green and dont dose phosphate!

i have alllot of light on that tank and co2 and have neglected the light and its been on for 10-12 hrs day, been busy workin, so i t the time back to 8 hrs maybe this will help some to!

i havent had algae in 4 years! dam i hate it being back to get me lol


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## Homer_Simpson (May 10, 2007)

customdrumfinishes said:


> ok thanks, its dark green and dont dose phosphate!
> 
> i have alllot of light on that tank and co2 and have neglected the light and its been on for 10-12 hrs day, been busy workin, so i t the time back to 8 hrs maybe this will help some to!
> 
> i havent had algae in 4 years! dam i hate it being back to get me lol


FWIW, I share your pain. After 6 months of having an algae free 10 gallon tank, with 30 watts and DIY c02, my tank finally sucummbed to green spot and black brush algae. You can check out my log at http://azdhan.googlepages.com/thelostworld

In my case, much of the algae materialized and took the tank by storm when I went overboard with trimming and plant mass(especially floating plant mass) was greatly reduced. The tank was in such bad shape that I seriously considering tearing it apart and starting over. For experimental and testing purposes, I decided to keep the tank running for another 2 months and here is what I did and believe it or not but the algae cleared up within a week of these changes:

(1) Reduced 30 watts compact fluorescent lighting to 20 watts total by replacing 2 15 watt compact fluorescent 6500 k daylight bulbs in the canopy with 2 10 watt 6500 K daylight compact fluorescent bulbs. I kept the photoperiod split to 8 hours split, 4 hours on, 2 hours off, and 4 hours on.

(2) Increased plant mass by adding several rotala indica stems and 2 additional dwarf tiger lotus bulbs.

(3) Added 5 Amano Shrimp to help clean up any dieing algae and any dead/decaying plant matter that could not all be siphoned out. Like spiderman, I could see the shrimp clinging to the areas of green spot algae trying to scoop it up and eat it. I believe that with the reduced lighting, the green spot algae was beginning to die back and the Amano Shrimp were feasting off the dead green spot algae residue.

(4) Decided to leave the filter media as is and only rinse it once a month, but continued with 50% weekly water changes. This may not have anything to do with plant growth, but I believe that the massive fish deaths in the tank may have had to do with too frequent(weekly) rinsing of the filter media(I may have been destroying the biological filter without even knowing it).

(5) Dosed Seachem Excel at 20 CC daily and continued with 2 litre DIY c02 injection. Note this is double the recommended dosage of Excel. If you try this in you case it would likely be around 16 CC daily as measured with a syringe.

The turnaround of the tank is short of miraculous, considering the tank was a real dog's breakfast only 2 weeks ago. Perhaps some of these suggestions may work for you. FWIW, I did increase phosphate dosing before making the above changes and the increased phosphate dosing did not appear to make a dent in the Green Spot Algae.


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## customdrumfinishes (Apr 4, 2008)

i know the excel will kill shrimp if overdosed. is the phos safe for shrimp?


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## Homer_Simpson (May 10, 2007)

customdrumfinishes said:


> i know the excel will kill shrimp if overdosed... QUOTE]
> 
> That depends on what you mean by overdosing? Many members with shrimp tanks double dose excel without any ill effects on the shrimp. I have a 5 gallon low tech where I double dose daily and have been for 3 months. The dwarf aquatic frog, otocat and amano shrimp are alive and kicking. These inhabitants are known to be the most sensitive to the effects of chemicals and water quaility. The Amanos have tripled in size in those three months and appear unphased by the Excel dosing.
> 
> The 10 gallon in question is also receiving and has been receiving a double dose of excel for the past two weeks. The 5 amano shrimp in the tank are still alive and kicking.


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