Do I really need to get rid of algae?

[katebet]

Hi - I'm brand new to this forum, but not brand new to keeping pond fish. I've had fish for over eight years now. Initially we had four, now we have fourteen - the original four have passed away and the fourteen now are their offspring. They are friendly little things and love to eat from my hand.

At our last house the pond got quite murky from green floating algae and a layer of algae (?) on the sides of the pond, but we didn't do anything about it and the fish were healthy and (obviously) bred profusely. Other than the original four - only a few died (they twisted into a u shape, which was heartbreaking). We have very hard water in Adelaide, South Australia, where I live.

At our new house the algae is back and the pond is getting murky - but no more so than at our previous house. I've read so many times that ponds need to be relatively clear and not have a lot of algae. I've read about different products to clear ponds, but my fear is these will harm my fish.

So - do I need to clear my pond? And, what products or methods are best to use that will not harm my fish?

Here's a photo of my pond as it is at the moment. It is quite an overcast day today - but you can still see the murk!

 

[JohnHuff]

Welcome to the forum!
First of all, how big is your pond and what kind of filter are you using? The more info you give us, the more we have to work with. Looking at your two pics, my initial impression is that all you need is a mechanical filter to filter out the algae. That is natural and won't harm the fish.

 

[dieselplower]

In general no the pea soup algae is not bad for the fish. What I would worry about are things like ammonia, nitrite, and nitrate. Pea soup water can actually help keep those numbers down. If you don't mind the green water, I'd say keep it. The fish won't mind.

 

[Waterbug]

Algae is good, it can keep ammonia low.

Algae is bad, it consumes O2 and fish can suffocate.

Algae is algae. Whether algae should be controlled or not purely depends on the pond keepers desires. If you were concerned about fish health you would test water parameters to get an idea of what needs correcting.

Asking if algae should be removed or not in a forum is kind of like saying you're currently driving down a road at 60 MPH and posting the question "should I turn left or keep going?" More data would be needed for a rational answer.

 

[crsublette]

At our new house the algae is back and the pond is getting murky - but no more so than at our previous house. I've read so many times that ponds need to be relatively clear and not have a lot of algae. I've read about different products to clear ponds, but my fear is these will harm my fish.

So - do I need to clear my pond? And, what products or methods are best to use that will not harm my fish?

Hmmmm. I wish they would have stated the "why" they think "ponds need to be relatively clear and not have a lot of algae."

The "algae clear" products can kill your fish and plants only if not following instructions and not knowing your total gallons, within reason.

Fish love algae. It helps to protect them from predators, acts as a bio-filter, and provides some nutrition.

"Relatively clear" pond is for the Human's interest rather than the fish's interest. Although, as with everything, there is one exception to this statement, which is dependent on your water's alkalinity.


First my question... When you say "We have very hard water in Adelaide, South Australia", does this mean the alkalinity is relatively high? Generally, the answer is "yes", but it would be good to know. :cheerful: :claphands:


Now the explanation.....

1. Alkalinity is the measure of your water's buffer capacity.

2. Buffer capacity is what manages your water's pH levels.

3. As you lose alkilinity, the buffer capacity reduces and causes your pH levels to change.

4. Constantly changing pH levels will stress your fish's immune system, but they will survive it, or survive the secondary infections cause of it, most of the time.

5. Your fish's immune system is also bolstered by hard water.

6. Hard water is the measure of your water's mineral content.

7. Water with a high mineral content will most often, not always, have a high alkalinity.

8. Algae and other biological filtration enjoys consuming the water's alkalinity. More algae you have, the faster your alkalinity is consumed.

9. More fish and higher feeding you have then more of the water's alkalinity is consumed by the biological filter. More fish ya have and higher feeding, the faster your alkainity is consumed.

10. Water changes with rain or soft, acidic water from the tap, or other source water, will also consume your water's alkalinity. More water changes with soft acidic water, then the tougher it is to manage your alkalinity.

11. If your tap water or source water is relatively alkaline, then it adds to your water's alkalinity.

12. Rinse and repeat back to #1.

See it come full circle. :blueflower:


Also, even at higher pHs, fish can still suffocate when there is O2 saturation due to the algae producing more and more carbon dioxide. Carbon dioxide is toxic to fish much like Nitrates are at high levels. Although, even at higher pHs, the increased alkalinity requires much more carbon dioxide to be created by the algae until it eventually suffocates the fish. This is why you should also have a good bubbler, or aerator, to pull the water from the bottom to the top. Move this water, and carbon dioxide, will help the gas to be released out of the water and dissolve into a fish safe compound.

If you have hard water with a low alkalinity, then the algae might cause problems due to consuming the alkalinity and water's alkalinity is not being replenished by the source water, but "hard water with low alkalinity" is not common.


So..... This leads me to asking my question above.

 

[katebet]

Thanks everyone for your answers - I'll do some investigation on the health of my pond as it stands, and let you all know.

Waterbug - I'm still learning and I DO care about the welfare of my fish - obviously - or I wouldn't be trying to get some information from the forum. I'd appreciate a little more understanding rather than the response you gave that:

"If you were concerned about fish health you would test water parameters to get an idea of what needs correcting.

Asking if algae should be removed or not in a forum is kind of like saying you're currently driving down a road at 60 MPH and posting the question "should I turn left or keep going?" More data would be needed for a rational answer."

I'm not an idiot...I'm just learning...

 

[Sunshine]

I'm having a hair algae problem this year, I think it has more to do with the weather since nothing has changed in the pond itself. Our weather has been strange, long Spring, wet and chilly and hardly a summer to talk about. I have a lot of lilies and not that many blooms. New bog this year and I'm constantly pulling the hair algae out of it so it don't kill my new plants. The algae on the sides of the pond, I leave alone. What hangs from the bio filter falls I pull out.

 

[Waterbug]

Thanks everyone for your answers - I'll do some investigation on the health of my pond as it stands, and let you all know.

Waterbug - I'm still learning and I DO care about the welfare of my fish - obviously - or I wouldn't be trying to get some information from the forum. I'd appreciate a little more understanding rather than the response you gave that:

"If you were concerned about fish health you would test water parameters to get an idea of what needs correcting.

Asking if algae should be removed or not in a forum is kind of like saying you're currently driving down a road at 60 MPH and posting the question "should I turn left or keep going?" More data would be needed for a rational answer."

I'm not an idiot...I'm just learning...

Didn't mean to imply you were an idiot. I'll explain. I don't mean to imply judgement by saying "If you were concerned about fish health..." but understand how you could take it as an insult. Sorry. It's suppose to mean literally what it says without a predetermined judgement. There have been many times I've kept ponds without testing because I wasn't overly concerned about fish health. I don't see anything wrong with that. I don't see it as cruel. The fish seemed healthy, water seemed fine, I had enough experience to guess ammonia wasn't a problem.

Then there were other ponds where I was concerned about fish health. Maybe the water didn't look good. Maybe it looked like too many fish in the pond. Etc. For whatever reason I was concerned for their health. IMO the very first step when I'm concerned for fish health is to test the water. It's pretty easy and cheap. I think it's a reasonable thing to do. I like to test for a few days to get an idea of what's going on unless testing shows an immediate problem.

Sure, I know in many forums people slam people for not testing. I assume that's what you thought my intention was. But to me this is all just a bunch of choices. You could keep your fish in the most perfect conditions, testing around the clock, and there will always be someone to come along and say you're not doing enough. That's crap. We do what we do and we shouldn't beat ourselves up.

There is a danger in clearing a green pond. The algae acts as a bio filter consuming ammonia. When the algae is killed almost overnight ammonia can spike. Not "will" spike, "can" spike. In most cases it isn't a big enough problem to kill fish. Testing water will tell you if there is a problem that you can fix. I'm just giving you the info to do what you would like. Most people, by far, don't test. I often don't test. It's an option. If you have the info you can make an informed choice based on your circumstances. I have no idea what circumstances you're in, your goals. You only asked about algae.

There is also a danger that when a thick algae bloom is killed the decaying algae consumes enough O2 to drop levels enough to kill fish. Again, your personal level of concern for the fish should dictate the level of testing you do. You could buy a pretty expensive dissoved oxygen meter if you were really super concerned about fish health. For a backyard pond I've never been concerned enough to do that level of testing. There are cheaper test kits, not very accurate, but maybe that would fit a person's concern level. For me I just watch the fish to see how they're doing. If they show signs of low O2 I'm ready to fix the problem. Most people do nothing and are probably unaware that there could be a problem. Nothing wrong with that any more than choosing not to buy a oxygen meter. The judging thing is just silly human crap...nothing to do with ponds.

There is also a danger that when a thick algae bloom is killed the decaying algae produce a lot of CO2 which is an acid in water and can crash the pH. Fish can and do survive pH crashes. Sometimes they don't. But in general, if a pond does crash because algae was killed, there is going to be an on going problem with unstable pH. Because a KH test is very cheap, very easy to perform, very accurate and the fix is extremely cheap, easy and safe, I choose to test KH before killing algae. Most people don't. I don't think they're idiots for not doing this...unless maybe if they have really expensive fish or are super concerned about the health of their fish. Some people name their Goldfish and health concern is very high. That's fine for them. I don't think they're idiots for testing too much. Who am I to judge? I'm not even interested in it because it's so boring. World is full of it.

So like I said, algae is algae. It's neither good or bad. It's strictly about choices. To me, informed choices are best. But, yes, it's a lot less typing to just say "algae is good" (which I have said many times) and "algae is bad".

 

[slakker]

In my opinion, the short answer is no, but you need to manage any negative impacts of algae. Ie; it uses up oxygen at night, it can clog filters, it can be unsightly Ito some people, etc.. But if you manage it so it doesn't impact the overall Eco system negatively, then I don't think you need to remove algae.

But if maybe easier to manage/remove algae than each individual negative symptom of it...

 

[sissy]

algae can be a pain but easy to solve if you cut back on feeding your fish .i feed mine only 3 or 4 times a week and use a little peroxide sprayed on the rocks and clean my filter with peroxide and water if needed .But hand removal to get the heavy stuff first

 

[Waterbug]

But if you manage it so it doesn't impact the overall Eco system negatively, then I don't think you need to remove algae.

True. Testing is an option for some people to determine if the system is being effected negatively. Some parameters, like KH, is difficult to judge without testing.

 

[katebet]

Didn't mean to imply you were an idiot. I'll explain. I don't mean to imply judgement by saying "If you were concerned about fish health..." but understand how you could take it as an insult. Sorry. It's suppose to mean literally what it says without a predetermined judgement. There have been many times I've kept ponds without testing because I wasn't overly concerned about fish health. I don't see anything wrong with that. I don't see it as cruel. The fish seemed healthy, water seemed fine, I had enough experience to guess ammonia wasn't a problem.

Then there were other ponds where I was concerned about fish health. Maybe the water didn't look good. Maybe it looked like too many fish in the pond. Etc. For whatever reason I was concerned for their health. IMO the very first step when I'm concerned for fish health is to test the water. It's pretty easy and cheap. I think it's a reasonable thing to do. I like to test for a few days to get an idea of what's going on unless testing shows an immediate problem.

Sure, I know in many forums people slam people for not testing. I assume that's what you thought my intention was. But to me this is all just a bunch of choices. You could keep your fish in the most perfect conditions, testing around the clock, and there will always be someone to come along and say you're not doing enough. That's crap. We do what we do and we shouldn't beat ourselves up.

There is a danger in clearing a green pond. The algae acts as a bio filter consuming ammonia. When the algae is killed almost overnight ammonia can spike. Not "will" spike, "can" spike. In most cases it isn't a big enough problem to kill fish. Testing water will tell you if there is a problem that you can fix. I'm just giving you the info to do what you would like. Most people, by far, don't test. I often don't test. It's an option. If you have the info you can make an informed choice based on your circumstances. I have no idea what circumstances you're in, your goals. You only asked about algae.

There is also a danger that when a thick algae bloom is killed the decaying algae consumes enough O2 to drop levels enough to kill fish. Again, your personal level of concern for the fish should dictate the level of testing you do. You could buy a pretty expensive dissoved oxygen meter if you were really super concerned about fish health. For a backyard pond I've never been concerned enough to do that level of testing. There are cheaper test kits, not very accurate, but maybe that would fit a person's concern level. For me I just watch the fish to see how they're doing. If they show signs of low O2 I'm ready to fix the problem. Most people do nothing and are probably unaware that there could be a problem. Nothing wrong with that any more than choosing not to buy a oxygen meter. The judging thing is just silly human crap...nothing to do with ponds.

There is also a danger that when a thick algae bloom is killed the decaying algae produce a lot of CO2 which is an acid in water and can crash the pH. Fish can and do survive pH crashes. Sometimes they don't. But in general, if a pond does crash because algae was killed, there is going to be an on going problem with unstable pH. Because a KH test is very cheap, very easy to perform, very accurate and the fix is extremely cheap, easy and safe, I choose to test KH before killing algae. Most people don't. I don't think they're idiots for not doing this...unless maybe if they have really expensive fish or are super concerned about the health of their fish. Some people name their Goldfish and health concern is very high. That's fine for them. I don't think they're idiots for testing too much. Who am I to judge? I'm not even interested in it because it's so boring. World is full of it.

So like I said, algae is algae. It's neither good or bad. It's strictly about choices. To me, informed choices are best. But, yes, it's a lot less typing to just say "algae is good" (which I have said many times) and "algae is bad".

Thanks Waterbug - I think I was being a bit sensitive yesterday... :redface: I really do appreciate your advice...

 

[Waterbug]

No problem.

 

[adavisus]

Probably the easiest, safest and pretty way to reduce an excess of algae is to unleash a surface floating plant which is easy to control when it builds up

Azolla shades, extracts fertility, is easy to dispose of as mulch around droughted plants

Regards, andy
http://www.flickr.com/photos/21940871@N06/
http://swglist.wordpress.com/

 

[katebet]

Okay - thanks everyone for all the information! It's been really, really helpful. I tested the water of our pond today and the readings for what I tested are Ph 8.4 (which I think is a bit high?), ammonia 0.25 ppm, Nitrate and Nitrite both 0. The tests I used were for aquariums, but I figure the recommended levels would be the same as for a pond.

My pond is about 450 litres (or 120 gallons approx) and I have a water feature with a pump, but I would imagine that would not cut it as a filter? Should I still get a separate filter?

And, lastly, here are some of my fish to thank you (they are a little camera shy...except when there are no cameras around... :huh:

One of the twins Dylan - who thinks he is Jaws George

Ursula the orange fish

The other twin The white one is possibly Flynn...