# THE solution against algae



## cichlidiot75 (Feb 22, 2005)

I gave a 15 Gallon tank to a friend, he wanted to keep fish so this way he could see if he likes it. I told him to get a Brislenose Pleco to eat algae, and work around that with other fish that can live with the Pleco.

He never bought the pleco. So after a month I went to take a look, and the water was clear, no algae on the glass, and spot on perfect real plants! So I went OMFG how did you do that, do you clean and change water every day?

His reply was this:

http://www.xs4all.nl/~buddendo/aquarium ... ld_eng.htm

It's a long article, take your time to read it, but it is worth the effort if you have a tank that is not suitable for plecos or other algae eaters.


----------



## prov356 (Sep 20, 2006)

> he wanted to keep fish so this way he could see if he likes it.


Wow, for someone who had never kept fish, he got deep into it in a hurry. I've seen that site and article before, but wasn't ready to expend the work involved in keeping parameters where they needed to be. I think that'd be the challenge. What's he doing specifically to keep phosphates and nitrates within the 'no algae' range?


----------



## PEZenfuego (Feb 9, 2010)

Honestly I think water changes would be a better solution. Dilution is the best solution to pollution. Still, I found it interesting. Thanks for the link.


----------



## prov356 (Sep 20, 2006)

It's not about pollution. It's about getting your nitrate/phosphate ratio set in a range that discourages algae. Water changes won't eliminate or discourage algae, so isn't really the solution to preventing it.


----------



## cjacob316 (Dec 4, 2008)

what causes phosphate in the tank though...

i guess the easiest thing to do would be figure how on avg how much phosphate you generally have and then use water changes to keep your nitrates at the correct amount. phosphates aren't something that increases is it?


----------



## prov356 (Sep 20, 2006)

> i guess the easiest thing to do would be figure how on avg how much phosphate you generally have and then use water changes to keep your nitrates at the correct amount. phosphates aren't something that increases is it?


Phosphate comes from the breakdown of organics. Also comes from some tap water like mine.

See Phosphates in the aquarium


----------



## PEZenfuego (Feb 9, 2010)

When it comes to removing phosphates and nitrates (ie algae food) the best route is to dilute them with RO/DI (for saltwater) or phosphate and nitrate free tap water. If both the nitrate and phosphate levels are 0 (or close to it) then you won't have algae problems.

Dilution is the best solution to pollution.


----------



## cjacob316 (Dec 4, 2008)

i have one aquarium with blue green algae, and it's a fairly new occurence, have no idea what's causing it


----------



## Rhinox (Sep 10, 2009)

cjacob316 said:


> i have one aquarium with blue green algae, and it's a fairly new occurence, have no idea what's causing it


Too much phosphate in comparison to nitrate, according to the article in the OP. Stands to reason that if you let a little bit of nitrate build up, your blue green algae should go away and you'll start to get the normal green kind.


----------



## PEZenfuego (Feb 9, 2010)

Rhinox said:


> cjacob316 said:
> 
> 
> > i have one aquarium with blue green algae, and it's a fairly new occurence, have no idea what's causing it
> ...


The more sensible option (in my opinion) is to try to rid your tank of phosphates. As waste breaks down both nitrate and phosphate will build up.

Throw some rowaphos in your filter and keep up with water changes.


----------



## prov356 (Sep 20, 2006)

PEZenfuego said:


> Rhinox said:
> 
> 
> > cjacob316 said:
> ...


So, you're suggesting that it's easier to keep nitrates and phosphates close to 0 using RO water or phosphate removers and water changes than to strive for a ratio outlined in the article? Maybe yes, maybe no. Seems like it sort of takes the topic off track though. Has anyone tried the Redfield ratio, and if so, can you let us know your experience with it? It's a good topic and I'd hate to see it get sidetracked.


----------



## prov356 (Sep 20, 2006)

> If both the nitrate and phosphate levels are 0 (or close to it) then you won't have algae problems.


Close to it, according to the Redfield ratio, will encourage blue green algae. Have you experienced something different? What were your values when you achieved an algae free tank?


----------



## cjacob316 (Dec 4, 2008)

sorry, yeah i do want to see some experience on this, especially for planted aquariums where nitrates are a must


----------



## prov356 (Sep 20, 2006)

PEZenfuego said:


> When it comes to removing phosphates and nitrates (ie algae food) the best route is to dilute them with RO/DI (for saltwater) or phosphate and nitrate free tap water. If both the nitrate and phosphate levels are 0 (or close to it) then you won't have algae problems.
> 
> Dilution is the best solution to pollution.


I see your coming from the reef keeping side, and so your view makes sense now, but freshwater is a different ball game. Very few fresh water keepers use RO. There is also rarely enough denitrification going on to help keep nitrates at or near 0 in a freshwater tank. The rules and methods of keeping reef tanks doesn't apply exactly the same to fresh water.


----------



## cichlidiot75 (Feb 22, 2005)

Yesterday I got some KH2PO4 (potassium phosphate) from my friend, I did a nitrate test first. Water change was necessary first to bring down the nitrate because it was too high for a stable Redfield ratio.

Our tapwater has a Redfield ratio of 115, which guarantees green algae growth. So adding Phosphate is necessary.

After the water change I added some Phosphate according to the calculator on the bottom of the website.

Usually, algae starts growing on the rocks and glass within 24 hours after a water change in my Tanganjika tank. Today, nothing. Really, this works like nothing else I've ever tried in 10 years of keeping fish.

My friend is doing this for a month now.

I don't know where you can buy KH2PO4 (potassium phosphate), in the USA, but here in The Netherlands we can get it a the pharmacy. You have to provide a statement what you will use it for and show your id and name your adress.

About a few reactions I've seen here:

1 It is good to have some nitrates (and phosphates) in your water. Especially with plants.
2 It is good to have nitrates between 1 and 20 milligram per liter
3 It is good to have phosphate between 0,1 and 2 milligram per liter
4 Water changes are still necessary to reduce nitrates.
5 For those who think all you need to prevent algae growth is a water change, you guys probably have tap water with a perfect Redfield ratio. Congratulations, I envy you all!

If you want to try this, then test your water, check the test results with the table and read the Redfield ratio. If you have algae in your tank the ratio will be "off" in some sort of way.

Then enter the test results in the calculator, and the calculator tells you what to do.


----------



## cichlidiot75 (Feb 22, 2005)

prov356 said:


> > he wanted to keep fish so this way he could see if he likes it.
> 
> 
> Wow, for someone who had never kept fish, he got deep into it in a hurry. I've seen that site and article before, but wasn't ready to expend the work involved in keeping parameters where they needed to be. I think that'd be the challenge. What's he doing specifically to keep phosphates and nitrates within the 'no algae' range?


He got green algae within a week like crazy, and that's when he found out that Corydoras are no the same as Plecos :lol:

So he searched the internet for ways to reduce algae and found this article. He tests the water and puts the values in the calculator, then does what the calculator tells him to do. Usually he has to add a tiny little bit of phosphate.

If you use the calculator it is really simple. Keep in mind it's using the metric system, grams and liters :thumb:


----------



## cichlidiot75 (Feb 22, 2005)

Today I tested my water again. Nitrate was 20 mg/l, Phosphate was 0,7 mg/l. This is a Redfield ratio of 44. Close, but not perfect.

The calculator advised a 25% water change and add 20ml of KH2PO4.

Now, after the water change, Nitrate is 10 mg/l, Phosphate is 1 mg/l. This is a Redfield ratio of 15. Spot on perfect. :thumb: *Bye bye algae!*

As you can see, with these values the water is anything but polluted!

I will keep you guys informed what will happen next week with the next water change.


----------



## prov356 (Sep 20, 2006)

A couple of questions.

How did you reduce the nitrate from 20mg/l to 8mg/l with a 25% water change? Is there something else going on with the water change?

I'm also wondering what type of test kits or equipment is used to get the kind of precision needed to accurately measure nitrate and KH2PO4.



> As you can see, with these values the water is anything but polluted!


I would agree. Algae thrives when light and nutrients are to their liking. Those same conditions may also be ideal for the keeping of certain fishes. Algae doesn't indicate a 'dirty' tank or unhealthy conditions for fish necessarily.



> I will keep you guys informed what will happen next week with the next water change.


Please do, thanks. Very interested thread.


----------



## cichlidiot75 (Feb 22, 2005)

prov356 said:


> A couple of questions.
> 
> How did you reduce the nitrate from 20mg/l to 8mg/l with a 25% water change? Is there something else going on with the water change?
> 
> I'm also wondering what type of test kits or equipment is used to get the kind of precision needed to accurately measure nitrate and KH2PO4.


Sorry, I misread the test result. Nitrate was 10 mg/l. My tap water is somewhere between 5 and 8, so to reduce it by 50% I don't need a 50% water change. Maybe I removed a couple of liters more and after the change added more water too, It's kinda hard to measure the exact amount of water I change with 15 liter buckets and a fish tank that is 240 liters with rocks in it.

I use the Sera test kits, they're recommended by the author of the article. He says no test kit for consumers is 100% accurate, but Sera and and Dupla will do the job. Tetra and Velda kits suck.

The KH2PO4 is the phosphate that you add. You can use the test tube from the test kit to measure the amount. You have to solve the Phosphate in RO water or destilled water. I use a solution of 1 gram per 50 milliliter, that is 20 gram per liter. You have to enter the solution ratio you use in the calculator on that website.

This also works the other way around, if your water is short of Nitrate you add KNO3 in the same way.


----------



## PEZenfuego (Feb 9, 2010)

I see Prov. It's hard to get used to the fact that people in the freshwater community aren't using ro/di or otherwise very pure water. The only downside to using it is that when keeping plants you may need additives and your pH will be very acidic. It is also very corrosive without additives. I am using a mixture of ro/di and tap just to ensure that my water is below 200 tds.

Learning about the levels of freshwater is incredibly less complicated than that of a reef system but as I have just learned...it is different.


----------



## mg426 (Nov 24, 2009)

I also come from the world of reef keeping. The general idea was that nitrate and phosphate were to be kept as close to zero as one could possibly achieve. Now my Mbuna tank runs at <10 PPM nitrate. A for phosphate I can not measure any at all with a Salifert phosphate Kit. I have however Been told that phosphate is one tricky elemnt to test for. Basically the idea is that if you have any algae(And I do) it will bind/Use the Phosphate as fast as it is introduced to the water. The Redfield ratio Looks very interesting to say the least.


----------



## cichlidiot75 (Feb 22, 2005)

The best would be to keep nitrate around 5 mg/l and phosphate to match for a good Redfield Ratio for an Mbuna tank. Planted tanks may want slightly more nitrate and phosphate.

For me, it's day 4 now that I'm working with the Redfield Ratio. On some rocks, the green algae starts fading to white, so it's dying. I also had some blue-ish algae, which does grow a little but the rate is extremely slooooww :zz: . There's still some algae in the substrate, which makes sense.

Next weekend I will clean the rocks, and substrate, because dead algae means biological breakdown and may increase phosphate. It's also a lot easier to keep the tank algae-free if there's hardly any present to start with.


----------

