Blue-Green Algae

[Arthur11]

If you have live plants in your fish tank, they can absorb all the nutrients that help the algae grow. These plants will make the nutrients lesser on the tank, which means fewer chances of the algae to grow. Meanwhile, algae-eating fish such as plecostomus and flying fox can help reduce the algae in the tank.

 

[Stan510]

That helps to have thick plant growth. But,if the BGA gets out of hand,it smothers the plants.
The only real cure is- avoid sand beds that WILL become nutrient sinks,go with a fine gravel or that sold for aquascaping. If you have an established tank- like me- and some sand? Then with every water change try and stir the bed without bothering the roots of plants. All you can do along with wash that filter out with every water change.
When even the Amazon tanks in Seattle get BGA ( and use sand) then you are going to have a never ending problem. My advice? take that sand out..fine gravel is much better.

 

[Bruce Leyland-Jones]

If you have live plants in your fish tank, they can absorb all the nutrients that help the algae grow. These plants will make the nutrients lesser on the tank, which means fewer chances of the algae to grow. Meanwhile, algae-eating fish such as plecostomus and flying fox can help reduce the algae in the tank.

As this is a thread dragged up from the relatively distant past, it'll be worth noting that Blue Green Algae is not an algae, but bacteria and, as such, it produces toxins.
We occasionally get blue-green algae outbreaks up here in our English Lake District and warnings are posted on the lake shore. The toxins produced can be fatal to large animals, such as dogs and even swimming tourists have become very ill as a consequence of ingesting waters contaminated by the stuff.
Obviously, it isn't good for fish.

 

[Stan510]

Also- no algae eating fish will eat slimy BGA. If it was only that easy...

 

[Bruce Leyland-Jones]

Also- no algae eating fish will eat slimy BGA. If it was only that easy...

...Because algae-eating fish won't eat toxic bacteria.

 

[Stan510]

Well,.it is also a primitive plant- it needs light to live. I have heard the Florida Flag fish will eat it. But,what if you don't want that aggressive little fish or the fact years can go by with none for sale at LFS? Same for Mollies who then overpopulate the scaped tank quickly?
If people got rid of fine sand substrate,BGA becomes much easier to really be killed off. I was just looking at a top notch scaped tank on youtube and what do I see growing beneath the front sand? BGA. None in the tank..but he missed the below sand line.

 

[Byron]

Cyanobacteria is a species of prokaryotic bacteria that uses photosynthesis like plants/algae, but it is not algae. It is also caused by organics in the presence of light. I have had sand in my 8+ tanks for almost a decade now, and cyano occurred twice in one tank and I dealt with it as I have described previously/elsewhere. Ironically that tank had a gravel substrate. I do not see how sand could be the culprit.

 

[Stan510]

Oh,it is. Sand seems to be a favorite haven for blue green algae to feed from. Sure gravel can cause it too,but I've seen that it took much drowned organics in gravel to cause an outbreak. Sand? Seems it only takes being in the aquarium to start the BGA headache.
Amano used sand just as open space filler. The plants were in his gravel grains. Even then,that sand I think isnt as fine as most pools sands are.
Add much light and wattage to sand is asking for perpetual trouble. Plus,I don't like that pool sands seem to starve plant roots of oxygen...anaerobic heaven for the BGA.

 

[Byron]

Oh,it is. Sand seems to be a favorite haven for blue green algae to feed from. Sure gravel can cause it too,but I've seen that it took much drowned organics in gravel to cause an outbreak. Sand? Seems it only takes being in the aquarium to start the BGA headache.
Amano used sand just as open space filler. The plants were in his gravel grains. Even then,that sand I think isnt as fine as most pools sands are.
Add much light and wattage to sand is asking for perpetual trouble. Plus,I don't like that pool sands seem to starve plant roots of oxygen...anaerobic heaven for the BGA.

Well, plant roots do not take up oxygen, they release it. If the sand has too much organic material, it could cause cyanobacteria, but it certainly is not the sand itself. There is no better substrate for any freshwater aquarium than sand, with the exception of Central American and Indian subcontinent biotopes where the rivers are fine gravels (if one want authentic biotopes). There is a natural water movement through open sand, as the water in the sand is heated by the bacterial activity and thus rises up into the aquarium to be replaced by cooler water drawn down into the sand. A sand substrate of one, two, three, or four inches depth (depth depending upon the specifics of the aquarium) is as healthy a substrate as one can have.

 

[Stan510]

No,it is not..4" of sand is nothing but a hatchery for hydrogen sulfide. I've seen it develop under a rock placed on sand. Not much chance a gravel substrate has that happen. Sand just interferes with proper root growth to the point they die off.
This whole fad of sand and not gravel? Is a bad one! Sand in nature is no comparison when pure filtered rain bubbles up or the like..that's 100% water changing 100% of the time. Its why a tree falls in the stream and no fish die from rotting leaves and all the tonnage of green wood ..the water is refreshed not recirculated.
I've done the pool sands thing and can say- never again. Not for a plant tank..never.

 

[Byron]

No,it is not..4" of sand is nothing but a hatchery for hydrogen sulfide. I've seen it develop under a rock placed on sand. Not much chance a gravel substrate has that happen. Sand just interferes with proper root growth to the point they die off.

Well, this is not proven out by most of us. You want anaerobic areas, that is the second part of the normal nitrification/denitrification process. And it does occur with gravel, I had it in my 33g tank with black gravel under all the rock and wood. But you leave these areas alone.

Considering that in nature plants live in sand, not gravel, or if not sand then mud which is even more compacting. I agree the aquarium is a different thing, but the point is still relevant. Sand is the best substrate for fish and plants.

 

[Stan510]

I strongly disagree.You have to take into account that 4" of sand is VERY heavy and packs down hard. When you add organic build up it becomes near cement. If you ever had an undergravel filter and Goldfish,you see that happen pretty fast. I remember back in the 80's in the book about natural aquariums that a 2,000 gallon tank of plants had just that happen to the sands they used..it reacted and became so impenetrable to roots,the whole huge tank had to be reset.
Sand is for nature...not home aquariums or their plants. Now,I'm not saying use that color coated large grained pea gravels sold...but their are grains of COURSE sands that are like fine gravel. I like that best and no more than 3" deep.

 

[CaptainBarnicles]

don't mind me...

 

[Stan510]

Mind you ,it was a German tank,using scientific models at the time. No American tank with Hippo bubblers
Halide lighting..state of the art everything..and the use of sand had to be abandoned.

 

[Byron]

These photos are of my 5-foot 115g Amazonian riverscape that ran for 6 years after I changed the substrate to sand. Plants were no better or no worse with sand than they had been with gravel. And when I tore this tank down to move (and sold it as I knew I wouldn't have room for the big tanks) the sand was in just as good shape as my gravel substrates had always been. Photos are May 27 and August 22, 2014 and February 24, 2015, the last three photos of the tank. The growth of the large swords is unmistakable.