What causes algae on the substratre

[anewbie]

On 1/8/2024 at 11:42 AM, Seattle_Aquarist said:

Hi @anewbie

Sorry for the delayed response, I was on vacation with my family over the holidays.

What I see in your photos is blue-green algae, aka cyanobacteria, which is a unique type of 'algae' in that it is part plant and part animal (bacteria).  I occasionally get it in my tanks like I suspect many hobbyists do, usually when I am 1) delinquent in doing my weekly water changes, 2) not changing sufficient water and allowing a build up of nitrogenous waste, 3) not cleaning my filter as often as I should.  I have also found it to occur when I have high light, insufficient plants, and/or poor water circulation.

Typically my first step is to physically remove as much of it manually.  I gently remove it from the leaves putting a finger on each side of the leaf and lightly squeezing from the stem to the tip.  Blue-Green Algae (BGA) comes off very easily, feels a little slimy, and has a pungent aroma.  For the substrate I siphon off the areas that have BGA removing the BGA and some of the substrate.  Then I add more substrate if needed.

After removing as much manually as I can I check to see if I have been lazy doing some of my maintenance, do a 50% water change, and clean my filter.

If the BGA consistently returns, and my maintenance and water circulation are good and the light isn't excessive, then I look at add additional remedies.  Some folks have had success killing BGA using a antibiotic (erythromycin) however I try to avoid using antibiotics in my tanks because diseases can become resistant to them if used too frequently and their is already too much in our environmental wastewater.  Also, if you use any sort of chemical remedy and too much of the BGA dies, then the dying BGA will deplete the tank of oxygen, the water will cloud, and the loss of fish may result.

About two months ago I had a bad outbreak of BGA in my 75 gallon discus tank.  I had gotten lazy and not cleaned the three (3) Fluval 307 filters for about seven (7) months and I usually clean them about every two (2) months.....my bad.  So I did what I suggested above, spent several hours manually removing the BGA from the leaves and hardscape and siphoned the BGA from the white pool filter sand substrate.  I got out as much as I could but I knew I didn't get it all so I looked for an alternative to antibiotics.  What I found was interesting.....combating one bacteria with another.  I read about Dr. Tim's Cyanobacteria Treatment for BGA (link to PDF) and decided to try it.  I had met Dr. Tim (Yes he has several science degrees) about 20 years ago at a aquatic expo in Seattle.   He had just started his own company after 17 years as the Chief Science Officer of Aquaria Inc., the parent company of Marineland Aquarium Products, Aquarium Systems (Instant Ocean).  His views on cyanobacteria were interesting but since his initial products were for saltwater applications I did not think too much of it.

I did my first experiment with Dr. Tim's in August with bad results.  I used both products (Refresh and Waste Away) on a 45 gallon as lost about a dozen Dwarf Neon Rainbowfish (Melanotaenia praecoxis)  - when they suggest starting with 1/2 dose on both products they mean it.  The dying BGA / bacteria clouded the water and caused oxygen starvation.

In early November I decided to try again on my 75 gallon starting dosing at 1/4 dose and increasing slowly over a couple of weeks.  The result was by Christmas almost all the BGA was gone and when I returned from vacation it had not returned.  I will continue to use the product once or twice a month as 'maintenance' but I was very happy with the results.  I found the best prices of both products on Amazon.  Hope this helps! -Roy

The filter is a sump with 'socks' and i clean the socks weekly though they are not clogged. It is a large aquarium 180 gallons. I could try chemi-clean but prefer to not use if this stuff will eventually go away. 

Once i had a different type of bga caused by nitrogen release from anerobic activity but that was fixed by very soft current flowing over the substrate to lift the gas to escape but this is different. The stuff is a lot coarser almost sheet like. 

The reason i favor chemi-clean over dr. tim (if i use something) is because i've used it before with success on a 29. At the time i had rams in the tank; the stuff died very fast the rams lived and i was happy and it never came back (I did add a lot of air stones); i'm very reluctant to use meds.

If it is cyano is there a negative to just letting it grow out of control - is the cyano bad for the aquarium (or fish health) ?

 

[Seattle_Aquarist]

On 1/8/2024 at 2:44 PM, anewbie said:

The filter is a sump with 'socks' and i clean the socks weekly though they are not clogged. It is a large aquarium 180 gallons. I could try chemi-clean but prefer to not use if this stuff will eventually go away. 

Once i had a different type of bga caused by nitrogen release from anerobic activity but that was fixed by very soft current flowing over the substrate to lift the gas to escape but this is different. The stuff is a lot coarser almost sheet like. 

The reason i favor chemi-clean over dr. tim (if i use something) is because i've used it before with success on a 29. At the time i had rams in the tank; the stuff died very fast the rams lived and i was happy and it never came back (I did add a lot of air stones); i'm very reluctant to use meds.

If it is cyano is there a negative to just letting it grow out of control - is the cyano bad for the aquarium (or fish health) ?

 

Per the Center for Disease Control:
"Cyanobacteria and cyanotoxins can harm fish and other aquatic animals in several ways. The toxins may directly kill the animals. When a harmful algal bloom caused by cyanobacteria decomposes, it can use up the oxygen in a body of water."

That is why water utilities try very, very hard to source water where there is not cyanobacteria - it's not good for our health either. 

[anewbie]

On 1/9/2024 at 11:33 PM, Seattle_Aquarist said:

Per the Center for Disease Control:
"Cyanobacteria and cyanotoxins can harm fish and other aquatic animals in several ways. The toxins may directly kill the animals. When a harmful algal bloom caused by cyanobacteria decomposes, it can use up the oxygen in a body of water."

That is why water utilities try very, very hard to source water where there is not cyanobacteria - it's not good for our health either. 

Ok. So if it gets much worse i'll treat with chemclean. Probably the same active ingrediant as dr. tim.

Yet another question; a 'sister aquarium' that was setup around the same time with the same substrate is not having any issues - one key difference is that aquarium has tap water (ec around 240  - gh 6); this aquarium i've been slowly softening with ro water per water change so it is much softer - with lower gh - around ec 120; gh 2ish).

So basically the aquarium being impacted has less nutrients than the one htat is fine... it might be unrelated to what actually triggered the cyano but maybe it will ring a bell?

 

(Also the fish density in the other aquarium is approx 2x this aquarium).

Edited January 10 by anewbie

[anewbie]

In the end this was cyanobacteria as many suspected. I fixed the issue using chemi-clean per instruction (under dosed a bit); seems resolved but will update this thread if (a) it comes back and (b) i can find the thread again (which is very difficult on this site) 😉

 

[anewbie]

pictures with the stuff removed:

 

Not sure why but the pink flamingo seems to be growing. Also that plant in the very back is more than 2 feet wide as this is a 4ftx4ft cube.