Begineers Guide To Algae

[Miss Wiggle]

hiya guys, don't post over here much. we get quite a few people in the new to the hobby section asking about algae, for the most part we're not talking people who want a fully planted tank, just 'normal' tanks with a handful of plants and hopefully not a massive on-going battle with the dreaded algae monster!!

You've got some really good pins over here, but they are quite technical and are also generally pitched at planted tanks not 'normal' tanks. So I've written up a little spiel on algae and plant growth in laymens terms to give to newbies to help them understand it.

Can you guys just have a read through, tell me if this makes sense and has at least some basis in fact!! Any constructive suggestions very much appreciated.

Algae like any other plant needs 3 things to live, CO2, food and light. You'll have lights in the tank and the tank may also receive direct sunlight so this gives one factor, the fish's poop effectivley becomes compost and gives food to the plants and there is always some CO2 in the water. If you have any body of water where you have all of these things then you will get some algae growth. However these are also the same things which make any live plants in your tank grow. Every plant and type of algae has different requirements for the amount of CO2 food and light they need. You can quantify this for the purposes of explanation as follows (the quantification isn't real, just representative to help explain). If your water naturally has 10 parts of co2, food and light, and the plants that you have need to use 10 parts of co2, 7 parts of food and 6 of light, once they've used this up they then can't make use of the left over food and light because there is no CO2 to go with it, this is where the algae comes in, it's much less demanding than the plants and as such can use up the remaining food and light with only trace amounts of CO2 and as such you'll get algae growth.

Essentially when people go for live plants in their tanks they aim for one of two methods, either 'high tech' which is where they add CO2, food and lights in such large quantities that the plants have everything they could possibly need and more, the plants then outcompete the algae and as such you just get good fast plant growth and very little algae. the second option 'low tech' is where you aim for the right balance of co2, food and light but only in relativley small quantities, the plants use it all up, grow relativley slowly but because you've not got 'left overs' the algae can't really take hold.

Now realistically, we all get some algae, you just need to scrub the glass to remove it or pull it out depending on the species of algae. However if you are getting a lot of algae growth then you need to adjust the balance of CO2, food and light getting to your tank so that you achieve a better balance and the plants get it rather than the algae. It's not an exact science as there's a lot of different factors, you generally just have to tinker until the algae dies back.

I'd then follow this with some links to the pns on algae for a bit of further reading....

 

[Egmel]

Sounds fairly straightforward to me and a good basic idea of where algae comes from.

A general point to add is that if you've got algae it's usually a good idea to increase your water changes as this removes algae spores.

If the tank is lightly planted then a DIY CO2 setup should help no end (CO2 is usually the limiting factor of plant growth). Alternatively there's a product called EasyCarbo or Flourish Excel which is not only a carbon fertilizer for your tank but also a mild algaecide

I await someone with more experience to add some further comments.

 

[Dave Spencer]

The key to understanding and ultimately defeating/suppressing algae is to appreciate what triggers it, not what feeds it. We all have everything present in our tanks that you have listed, as in light CO2 and nutrients, but we don`t all have visible algae.

Nitrates and Phophates are always the two main factors that are blamed, yet I can add these to my tank to excess and never see algae. No peer reviewed articles here, just good old observation, drawing me to the conclusion that nitrates and phosphates do not cause algae.

Algae has three signals it looks for to trigger a bloom. Light, unstable CO2 and ammonia.

Light is ultimately easy to control in fish only tanks, because there is no real need for the kind of levels that will trigger any significant algae bloom. In high light planted tanks, controlling light at the immature stage of the tank is key. The light is initially reduced, but increased as plant mass increases. I can now feel at what point I can use full light intensity in a new tank, but it requires practice. Add these kind of light levels to a fish only tank and algae will be unstoppable.

The unanswered question regarding light is, how come a heavily planted tank can remain algae free at high light levels, yet a fish only tank will become an algae farm?

Arguably the greatest cause of algae in our tanks is unstable CO2. If you have BBA or staghorn algae, then you have CO2 issues IME. In most cases, keeping the CO2 stable and in excess will prevent either of these two types of algae rearing their ugly heads. In fish only tanks, it has been argued that CO2 fluctuations arising from water changes triggers the algae. The recommendation here is to lay off the water changes for a while, if possible.

Ammonia present in imperceptible levels in the water column is another trigger. The nitrogen in ammonia is readily available to plants and algae alike as their first choice for the element. As always, it is the simplicity of algae that allows it to take advantage of the situation almost immediately. A lot of people gravel vac, but I sometimes wonder if this is doing more bad than good, as the disturbance of the substrate releases background levels of ammonia back in to the water column, and the readily available N triggers the algae.

Overstocked tanks will have these background ammonia levels due to fish waste, plus the possibility of the fish load depriving the filter bacteria of some O2, preventing them from increasing their numbers to combat the increasing ammonia levels. This is where green water can occur IMO, having read many posts on this forum. Still, at least the algae is stripping the water column of the ammonia, and could be protecting the fish!

I can trigger algae with monotonous regularity using light, CO2 and substrate disturbances, but I can also defeat it just as easily by understanding what triggers it.

The irony of all of this is that the best way to suppress algae is by supplying everything its needs to excess, but in a planted tank with a high nutrient uptake. These are the most susceptible tanks to algae when run improperly, but are the most algae free when run correctly. I never have to wipe the glass on my most established "hi tech" any more, and haven`t needed to do so for months.

As for excess nutrients causing algae, planted tanks show this to be incorrect. In fact, they show the opposite. Deprive plants of any given nutrient and they will eventually start to suffer, leaching ammonia across their cell walls and triggering algae.

People blaming nitrates and phosphates for algae have been holding the hobby back for ages, causing people to quit due to unresolved algae issues. Most of us in the planted side of the hobby have realised the above premice to be untrue, and run 99.9% algae free tanks in conditions that should be algae heaven.

I often get flamed for making the above observations, and moving away from the tired old nitrate/phosphate argument. All I have done is observed what is happening in my tank, having been prompted by Tom Barr. I don`t need any peer reviewed articles quoted to me about waterways in Florida or wherever, because I understand and can control what is going on in my tanks.

Remember, control algae by controlling what triggers it, not what feeds it.

Light.
CO2.
Ammonia.

The above is largely my observations, and I am sure others can give a bit more to this thread.

Dave.

 

[aaronnorth]

I agree with dave, also, CO2 doesnt cause algae, it is fluctuating CO2 that causes it, and algae doesnt need additional fertilisers either, it just needs light. When i first set up a tank, it had plastic plants, no CO2, no ferts, and 1WPG (low light) and i still got algae. I think you need to go in dpeth with some of the points you have explained.

Sorry if i am being to criticising!

 

[SuperColey1]

All correct above from Dave and Aaron. We've tried to explain to many people on here many times that excess nutrient doesn't cause algae otherwise we would all have to have $million laboratories measuring plant uptake to the ultimate precision to avoid any excess.

This has been proven to be nigh on impossible due to many variables such as, today the plantmass is less then tomorrow due to growth and therefore the uptake 'should' be more tomorrow, different plants use differing amounts of the nutrients to others etc. etc.

Therefore with no $million making calculations daily to guide us we should have algae, but don't. Or at least not to the extent where you can instantly be bothered by it.

As stated above also stable CO2 is the ultimate target these days and we are forever trying different methods to get the diffusion stable. For example external reactors, diffusors, powerheads with specially adapted impellors, Internal venturi reactors and so on. The list is large and grows with each minute as people experiment with new methods and then post their findings.

So is the algae article to be aimed at all to understand why they get algae or how to get rid of algae. In essence if you have a planted tank then you can (albeit a huge learning curve) control algae to the point that it is minimal but never get rid of it. In a non-planted you will be able to keep the growth of algae slow and controllable but only by keeping the light low. This is why fish tanks have such low 'stock' lights when you get them and only recently have they been adding a little more as they want to get the planted folk to buy their tanks.

Please don't post it with the excess nutrients cause algae theory though. We have a frustrating time on this forum trying to correct the 'phosphate haters' when they answer this question. We continue to do so while they lambast us for our 'unproven' theories whilst they roll out the age old 'phosphate causes algae' or 'excess nutrients cause algae' when we could give you a very good way to show that this is untrue. (One of Dave's previous 'proofs' below) Some people who used to post on this forum have given in and now concentrate on the Plant forums, while leaving the 'phosphate' haters to mislead people. We will continue to give the facts out but a lot of the threads can be very contradicting these days leaving the OP confused and once an argument breaks out between the 2 contradicting parties (which often happens) the OP has had enough and walks away from the thread not knowing which side is telling the truth.

This is one of my favourites that I have seen from Dave Spencer. These are my words not his as I can't find remember the thread it was in and it was a long time ago.
Take a bleach cleaned tank, rinse it with RO water. Now the tank is devoid of any contamination. Fill it with RO water (no substrate) This tank now has water H,O BUT no nutrient (N,P,K,Mg,Cu,Fe,Zn,Ca etc) at all apart from CO2 which will naturally pass into the water as will oxygen via gaseous exchange at the water surface. Put the lid on and leave it for a month. After the month is there any algae in the tank? Yes. Why? There have been no nitrates, phosphates etc added in any form because the RO water was devoid of them. So this disproves the excess nutrient theory.

I am pretty sure as others are that algae is triggered by some form of N and that the algae utilises it first. How would this apply to the RO only tank? I would assume there is a way that contamination through the air (any rotting material like dust, insects etc) causes the trigger.

Andy

 

[Egmel]

Ok, so we've come to some conclusions about what causes algae, ammonia levels (often lower than detected by our test kits), unstable CO2 and higher lighting.

So what's the most practical generic advice we can give?

All Tanks - Keep on removing what you can. ensure you're not overstocked/overfeeding. If no obvious ammonia/water quality issues then reduce water changes.
Tanks with a few plants - ensure lighting is manageable (~1wpg and photo period of ~8-10hrs), If possible improve CO2 - maybe a DIY kit or carbon fertilizer (Flourish Excel or EasyCarbo). (Alternatively suggest they might like to investigate going heavily planted and point them over here! )
Tanks with no plants - reduce lighting so that it's enough to see the fish by but that's all that's needed (remove reflectors maybe even use some form of crude filter).

Does that sound logical? I know it's a lot more complex than that and if it's something like BGA or BBA then there are special ways to deal with it - maybe a link to an 'identify your algae' guide would be good.

 

[Dave Spencer]

I guess your problem here MW is that you will be writing an article that could prove controversial, albeit unnecessarily so, in my opinion.

If you wish to write something that 95% of people will praise, and ask to be pinned, go with the nitrate/phosphate thing. Those of us that believe otherwise will probably be too jaded to bother questioning it.

Still, good luck with it. I am sure you will do an admirable job, and probably argue your views in the article in a far more reasonable and friendly fashion than most of us plant heads ever could.

Dave.

 

[Miss Wiggle]

I guess your problem here MW is that you will be writing an article that could prove controversial, albeit unnecessarily so, in my opinion.

If you wish to write something that 95% of people will praise, and ask to be pinned, go with the nitrate/phosphate thing. Those of us that believe otherwise will probably be too jaded to bother questioning it.

Still, good luck with it. I am sure you will do an admirable job, and probably argue your views in the article in a far more reasonable and friendly fashion than most of us plant heads ever could.

Dave.

sorry i haven't been able to get to this post in a couple of days, i appreciate all your feedback and thoughts though.

generally if i'm writing advice for beginners i try not to take the 'easy route' by giving obvious but not technically correct answers but instead try to find the truth (or the most likley sides to an argument) and just present it in a palatable way. don't always manage but hey we can only strive for success!!

what i've always been told is to manage algae growth you need to understand it, so that would be the key point to the article, just to explain why we get algae and what triggers excess growth, people from there should be able to see the possible solutions to controlling it, and obviously can be directed over to the planted forum for more detailed info from you guys in the know!

so in a tank with no added Co2, there will obviously be some Co2 in the water, am I right in thinking this fluctuates through day and night as the plants photosynthesise (is it still called that with underwater plants ) however this would not be classed as unstable Co2 would it? Do we replenish Co2 with water changes? Do people have differing levels of Co2 naturally in their water from different water companies much as we have different base levels of nitrate etc.

in a way it is right about excess nutrients being one of the causes of algae, however the nutrient which causes it is ammonia rather than nitrate or phosphate.

 

[SuperColey1]

CO2 will fluctuate through the day and night in all tanks. What we in the planted side try to achieve is a maximum for when the lights start (the photoperiod begins) so that when the plant wants the CO2 there is plenty there. After it has gotten this start to the day there are people who turn the CO2 off after a few hours, some leave it on till 2 hours before the end of the photoperiod and some leave it on 24/7. There is no hard and fast rule to how long to keep CO2 on for and we all tend to choose what we think works best for us. The stability is that every day when the lights come on we have a decent amount of CO2 and that it doesn't run down too quickly. The rest of the day will obviously fall until the next day when it starts to be built up again. This is why we also moan about the constant 'Ph fluctuations kill fish' theory because our tanks will rise and fall approx 1ph each day with the CO2 and max to minimum etc.

What is suggested in a non CO2 injected planted tank is actually quite the opposite of topping up the CO2 with water changes. What is proposed is that there is more dissolved CO2 in the tap water than there is naturally in the tank from Gaseous exchange at the water surface. So to do a water change will indeed 'top up' the CO2. Problem with this is that this 'top up' then means the CO2 is unstable.

This is why non CO2 tanks have minimal water changes reccommended. Every 6 months is often quoted by Tom Barr!!!.

This of course doesn't apply to non planted tanks as far as I know.

The chemists will explain the excess nutrient theory but as I read it we can only explain it from a planted side of things. I don't know how it would affect a non planted tank because there will always be excess nutrient in the tank. If people are worried about excess nutrient in a non planted tank they can always use Zeolite or carbon in their filters.

Andy