# 3 Week Rule?



## bjorn (12 Dec 2010)

I read recently somewhere an advice about the common green algae, it mentioned that you're better off leaving it alone for at least 3 weeks and it will die out by itself. The 3 weeks was due to it's short life cycle and by trying to remove it, like scraping it off the glass, you would just make it re-seed so to speak. 

Is this true, does it really work by leaving it alone for 3 weeks?

(My 4 little Oto's are doing a fine job of cleaning algae but they are not quite capable of tackling all of the glass surfaces on their own.)


----------



## ceg4048 (12 Dec 2010)

Hi,
    You need to be certain which algae you are talking about. We don't use the expression "common green algae" because they are all common and many different types are green, so that expression doesn't help at all. The algae type that is being referred to is Green Dust Algae or GDA because it looks as if there is dust on the glass. This algae is caused by poor levels of CO2 and nutrients so if you have this then you need to increase the levels of both. GDA is cyclic, as is the brown Diatomic algae that is seen at tank startup. Both are triggered by high incident light.

As long as you improve flow, CO2 and nutrients then yes, the technique suggested is to leave the GDA alone for several weeks until it completes it's life cycle and it will go away. The problem of course is that most people struggle to get CO2 right so this is not nearly as simple a plan as it sounds...

Cheers,


----------



## CeeJay (12 Dec 2010)

Hi bjorn

Personally I would get rid of any 'green' algae manually as your Oto's only eat the diatom algae (which is brown), which you can get in the first 6-8 weeks of setting up a new tank. After that it should disappear on it's own anyway. Just make sure you feed the Oto's some suitable food after this time, or they may get very hungry indeed.
The question is, why have you got green algae?
Some tank specs (lighting and duration, filtration/circulation, fert regime, tank size in gallons or litres, CO2 or not, etc.), will help us identify the problem.


----------



## CeeJay (12 Dec 2010)

doh. Clive popped up as I was typing.........again


----------



## ceg4048 (12 Dec 2010)

Sorry mate...  

Cheers,


----------



## bjorn (13 Dec 2010)

The description of GDA sounds about right, it's like dust on the glass. As there isn't a huge amount of it, I've avoided touching it as I kept the 3 week life-cycle in mind. 

According to my drop checkers the CO2 levels are ok (lime-green). I did a 50% water change yesterday but took readings before I did. PH was high and KH had gone down since last change:

PH 7.5 or 7.6 
KH 13
No3 25mg/l

After the water change I increased CO2 from 1-2bps to 3 bps to try and lower the PH which seemed high. My problem is that our area has very hard water (the Chilterns is all chalk).

When I tested the PH today it's gone down to PH 7.2 and  KH13-14.


By the way a bit worried about what was mentioned of the Oto's, i thought there would be a constant supply of food by natural occurring algae!


----------



## Tom (13 Dec 2010)

Don't worry about the pH or KH. I used a nice pretty sand in my nano, only to find out it was like pure calcium! Very high pH and hardness, no problems (any more, but that's another issue!!!) 

Keep an eye on the Otto's bellies - they should have a nice fat-ish stomach.


----------



## bjorn (13 Dec 2010)

Here is a image of the tank so you can see that the algae isn't that extensive, keep in mind I'm new to this so it's a bit amateurish.. The tank is around 6-7 weeks now I think.


----------



## ceg4048 (13 Dec 2010)

Hi bjorn,
             First of all, you need to stop testing because you haven't yet learned how to interpret the data that the test kits are giving you. Also, you may not realize that test kits are very inaccurate. Nitrate test kits are the least reliable of all test kits. The combination of these two factors usually spells doom for most inexperienced hobbyists.

I can see from your responses that you are already becoming addicted to test kits. This is like a drug and leads you to a dead end. Algae only ever appear in our tanks when we have some combination of high lighting, poor nutrient levels and poor CO2. So if you have algae and your test kit tells you that everything is "OK" then you have to immediately conclude that your test kit is rubbish, because algae know a lot more about your water than any test kit could ever possibly dream of knowing. The problem is that if you continue along this path of trusting test kit readings then there is sure to be another algae waiting right around the corner. Worrying about test kit readings and water parameters is one of those psychological barriers that impedes our progress because they are all severe optical illusions.

Another illusion is that somehow fish can solve your algae problems. Plants in poor health result in algal attacks. Fish can never address this fundamental issue, so you need to forget about what the fish can do about algae. Algal blooms can only ever be addressed by optimizing plant health. When plants are healthy then algae disappear. If the fish clean up minor unsightly algae on the hardscape then fine, but fish cannot prevent algal blooms.

So if you continue to trust your dropchecker despite the obvious evidence of poor CO2 you're going to have to wait a lot longer than 3 weeks. by that time you won't be able to see through the front glass. Have you read the dropchecker article in the Tutorials section? have you filled the dropchecker with 4dkh water? Is the dropchecker a bright lime green by the time the lights go on? Do you have a valid nutrient dosing program as described in the Tutorial section or by JamesC's dosing guide? If the answer to any of these questions is "No" then you are already in trouble and this minor outbreak of GDA is a signpost, warning you of more serious troubles to come.

Cheers,


----------



## chilled84 (13 Dec 2010)

bjorn said:
			
		

> Here is a image of the tank so you can see that the algae isn't that extensive, keep in mind I'm new to this so it's a bit amateurish.. The tank is around 6-7 weeks now I think.



Can i ask? Is the reason for the glowing pipe and Co2 defuser disk due to UV light? Could this cause you problems too?


----------



## CeeJay (13 Dec 2010)

bjorn said:
			
		

> By the way a bit worried about what was mentioned of the Oto's, i thought there would be a constant supply of food by natural occurring algae!


Once the diatom algae is gone they will struggle.
I feed mine algae wafers and cucumber, if that helps  

PS
Is it me, or is that drop checker a bit on the dark side?


----------



## bjorn (14 Dec 2010)

The light and the colour of the  drop checker is just because of my camera and the angle I took the photo on. It doesn't look like that when you stand next too it.

I've ordered "Hikari Tropical Algae Wafers" and "Hikari Tropical Sinking Wafers" to feed the Oto's with. Do love those little fish, I'd have those over any others any day.


----------



## dw1305 (15 Dec 2010)

Hi all,
Bjorn you need to feed your_ Otocinclus_, they are actually long lived fish (at least 4 years) if you can get them feeding on non-natural food. I always keep a small slice of cucumber/sweet potato/courgette/blanched green bean or bell pepper in the tank for them. They are often reluctant to eat algal wafers etc., but if you fix vegetables to some hard landscaping they will find it, and hopefully recognise it as food. I use an elastic band to fasten the vegetable to a bamboo cane, with the cane always in the same position in the tank. They may initially ignore the food until softens, so I usually replace the vegetables about every 48 hours. One advantage of cucumber is that you can stud it with wafers, and they fish may eventually feed on these as well as the algae and vegetables. I have some that will eat both vegetables and wafers, but one or two that will only eat vegetables, even when in the tank with wafers available.

cheers Darrel


----------



## bjorn (15 Dec 2010)

Thanks, Will do! I did just get the wafers and they don't seem to be interested as you have found.


----------

