# what about algae under the gravel?



## BBradbury (Nov 8, 2010)

*Algae in the Substrate*

Hello Bla...

Algae is a sign of a healthy tank, so some isn't bad at all. If you have a considerable amount, this means you have an unstable water chemistry. This is typically the result of feeding the fish too much or overdoing the commercial plant fertilizers. Commercial ferts have a way of messing up the water chemistry.

The only way I know to maintain even water properties is by removing and replacing a lot of tank water and doing it at least every week. I replace 50 to 60 percent every 6 to 7 days religiously. This keeps the water stable and free of excess nutrients. The longer the same water stays in a tank, the more it loses it's ability to sustain whatever you have living in it. 

Success in this hobby is 99 percent about the water. If you're a good water keeper, you'll have no tank problems.

B


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## Kathyy (Feb 22, 2010)

If you take an old bit of flat plastic, aka credit card, run it straight down between glass and substrate you will roll new substrate next to the glass and algae out of sight and possibly kill it. Works great.


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## Blacktetra (Mar 19, 2015)

Kathyy said:


> If you take an old bit of flat plastic, aka credit card, run it straight down between glass and substrate you will roll new substrate next to the glass and algae out of sight and possibly kill it. Works great.


thanks Kathy, I may try that. It would at least remove most of it from sight, and if it doesn't get any light, maybe it will die. I'll put some black electrical tape over the spot it's growing and see if the low light kills it too.


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## Tbell805 (Apr 26, 2015)

Since it is photosynthetic, in theory putting it under the gravel would kill it but then you will be releasing the phosphates or nitrates or whatever it has been using to grow back into the water column. Maybe pick up on water changes a little and that will take away the nutrients it is using. Since it is not full grown bloom I would deal with it. It really sucks when you neglect a small piece and then it takes over.


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## somewhatshocked (Aug 8, 2011)

There is little reason, unless fertilizing like crazy and stocking out-of-control, to do 50-60% water changes so frequently. It's potentially dangerous for new hobbyists, outdated information, misinformation and contradicts modern knowledge within the hobby.

Algae comes from an imbalance of lighting and nutrients. It's old hat, now misinformation, to suggest that overfeeding is typically the cause of algae. It's not. Lighting + nutrients = the cause.

Commercial fertilizers do not "mess up" water chemistry if used appropriately.



BBradbury said:


> Hello Bla...
> 
> Algae is a sign of a healthy tank, so some isn't bad at all. If you have a considerable amount, this means you have an unstable water chemistry. This is typically the result of feeding the fish too much or overdoing the commercial plant fertilizers. Commercial ferts have a way of messing up the water chemistry.
> 
> ...


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## Jeff5614 (Dec 29, 2005)

somewhatshocked said:


> There is little reason, unless fertilizing like crazy and stocking out-of-control, to do 50-60% water changes so frequently. It's potentially dangerous for new hobbyists, outdated information, misinformation and contradicts modern knowledge within the hobby...


A 50% water change every 6 to 7 days is potentially dangerous, outdated and contradictory to current knowledge? Please explain.


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## BBradbury (Nov 8, 2010)

*Water Changes*

Interesting comments on the water changes. Never heard of fish having a problem with too much clean water, it's typically when the water isn't clean. But, to each his or her own. I'll stick with the large, weekly water changes.

Good talking with you.

B


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## somewhatshocked (Aug 8, 2011)

Yes, it's contradictory to current knowledge/practices in the hobby. 

Unless you're dosing big time and/or know you need to change that much water, there's little reason to do so. Feel free to use the search function here on the forum to dig around a little bit about water params. Swapping huge amounts of water could potentially be deadly with sensitive fish or inverts if someone doesn't know what they're doing.


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## Mariostg (Sep 6, 2014)

Blacktetra said:


> thanks Kathy, I may try that. It would at least remove most of it from sight, and if it doesn't get any light, maybe it will die. I'll put some black electrical tape over the spot it's growing and see if the low light kills it too.


I did something similar in the past. It worked. I bunched a towel against the glass.

Sent from my SGH-M919V using Tapatalk


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## Daisy Mae (Jun 21, 2015)

somewhatshocked said:


> Swapping huge amounts of water could potentially be deadly with sensitive fish or inverts if someone doesn't know what they're doing.


Agree. 
And not all tap water being used for WC is created equal, some have more minerals, some have less.
@Blacktetra - good luck with the algae issue.


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## Kathyy (Feb 22, 2010)

Not changing water is harder on the fish I have as the more I change the closer it stays to the tap water. I don't have hard to keep critters though and my tap water is of good quality, I just need to treat it for chloramine. When I only topped off the tank to silence the nagging sump pumps for a number of months the water clearly lost mineral content and even 10% water changes stressed out one of the older fish very seriously. 

The more nutrients I put in the water the better. I use inorganic salts and they don't promote algal growth as much as the nutrients added by fish and plant wastes.

The algae is there whether I see it or not. If my plants are growing well a spot of this or that doesn't mean the tank is going to crash and burn because there is a bit of algae I bury or scrape off and lose.


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## Blacktetra (Mar 19, 2015)

BBradbury said:


> Interesting comments on the water changes. Never heard of fish having a problem with too much clean water, it's typically when the water isn't clean. But, to each his or her own. I'll stick with the large, weekly water changes.
> 
> Good talking with you.
> 
> B


Thank you for being polite. Somewhatshocked was perhaps a bit over forceful in their statements. However "clean" water for my fish isn't why this thread was started. Some blue green algae under my substrate is. I could do massive water changes but my softer water would starve my plants unless I also re-dosed fertilizer with each change. This would be a waste of my fertilizers given I already do a 20% change once a week. So while I appreciate the recommendation, it doesn't address my problem.

Bump:


Kathyy said:


> Not changing water is harder on the fish I have as the more I change the closer it stays to the tap water. I don't have hard to keep critters though and my tap water is of good quality, I just need to treat it for chloramine. When I only topped off the tank to silence the nagging sump pumps for a number of months the water clearly lost mineral content and even 10% water changes stressed out one of the older fish very seriously.
> 
> The more nutrients I put in the water the better. I use inorganic salts and they don't promote algal growth as much as the nutrients added by fish and plant wastes.
> 
> The algae is there whether I see it or not. If my plants are growing well a spot of this or that doesn't mean the tank is going to crash and burn because there is a bit of algae I bury or scrape off and lose.


to prevent water from losing minerals you can dose them, I use equilibrium for this. If you top off then you're slowly altering your water chemistry. Which is why I do 20% water changes once a week in addition to dosing some equilibrium. If H2O is the vast majority of what evaporates off of our tanks, and we top off with anything but distilled, then we're slowly adding more and more of the compounds that neither our fish or plants have use for.
In your case, making regular water changes is a good fit. You stay close to your tap and keep the less desirable compounds at an equilibrium with your tap water. Same with me, I just need to dose Equilibrium to help with Ca and Fe deficiencies in my tap.


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## dukydaf (Dec 27, 2004)

I had a similar situation to yours @Blacktetra. While I agree that some algae is generally part of a healthy aquarium, cyanobacteria is not part of a healthy aquarium. 

You can check my story with BGA in the post from today in my signature. In short, had some under the substrate like the OP for a long time and ignored it. After a week with no CO2, I had a huge BGA bloom that took me 2 months to recover from. Moral is, if you keep your CO2 up and high(enough) NO3 levels I would not worry.

Keeping sunlight from it does not really work in this setup. Even if you cover the exterior of your aquarium, light will be reflected from the glass to back into the top part of the substrate. Also, in my experiments I kept the algae in complete darkness for 10 days and once re-exposed to light it just grows.

I am thinking that injecting some erythromycin solution into that area of the substrate will most likely kill it. The idea with the card and push it to the bottom might be a good control measure as well.



somewhatshocked said:


> if someone doesn't know what they're doing.


Of course everything is dangerous if you add that condition. That is why I recommend to people who just start the hobby to buy guppies and Anubias nana.


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## Blacktetra (Mar 19, 2015)

dukydaf said:


> I had a similar situation to yours...
> 
> Of course everything is dangerous if you add that condition. That is why I recommend to people who just start the hobby to buy guppies and Anubias nana.


Thanks, I'll consider covering it with more gravel, and then injecting some H2O2 as well. I've reduced my lights and increased my ferts as I am seeing some signs of deficiency in my plants.

I'll also be far more cautious now that I know it may very well spread if I don't take care of it now.

As for guppies. Who would EVER recommend GUPPIES?! If you do, I certainly hope you suggest only getting males, as all it takes is two, and a year later you have a serious overstocking problem.


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## Kathyy (Feb 22, 2010)

Many times I have seen a bit of CB at the substrate/tank intersection and buried it without getting any CB plague. I've scraped BBA off something and lost the clump and no plague. I've scraped GSA off and no plague. If you bury the CB and it comes right back then inject H2O2, look at circulation, nitrate and all that but not if it happens once. If the edges are webby then it is spreading, if peeling then it isn't happy. 

Cyanobacteria is a perfectly ordinary occupant of a fish tank. Don't stress if you see some. Last year after starting the tank clean up last fall a large patch of CB [about 12" long and 6" tall] formed on the back pane of the tank where the thick hornwort had impeded water movement and I watched it after the hornwort mat was reduced in size. It moved towards the filter return day by day and the leading edge was peeling away which I found odd. That is usually a sign that it is on its way out yet it continued to move and algae moving has to be due to growth. Got tired of watching it and took the water level down below it at a water change and wiped it up and out of the tank with dry paper towels and the creepy green ghost was gone for good. It formed because of the lack of flow and survived even though the situation was changed but it couldn't come back after the situation changed.


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## Blacktetra (Mar 19, 2015)

Kathyy said:


> Many times I have seen a bit of CB at the substrate/tank intersection and buried it without getting any CB plague. I've scraped BBA off something and lost the clump and no plague. I've scraped GSA off and no plague. If you bury the CB and it comes right back then inject H2O2, look at circulation, nitrate and all that but not if it happens once. If the edges are webby then it is spreading, if peeling then it isn't happy.
> 
> Cyanobacteria is a perfectly ordinary occupant of a fish tank. Don't stress if you see some. Last year after starting the tank clean up... survived even though the situation was changed but it couldn't come back after the situation changed.


I've covered it with black electrical tape to reduce photosynthesis, I've reduced what I know was a high light level for a non-co2/low-tech tank. I heaped some more gravel on top to help block light, and injected some H202, it's losing and in retreat. Especially now that my tank is better balanced (less light, which I had up high to help feed the oto cats). What I find strangest, is that my highest concentration of algae, (thread, fuzz and now this CB/BGA) is actually right where the flow is highest. I am beginning to think it's a result of my filter building up biological bacteria which feed on my ferts, and then the high-flow areas have none, and then the low-flow areas still have some. Just a guess. Either way the algae is in retreat, I just wanted to make sure that seeing SOME CB doesn't mean "your doomed in 1 week if you don't move NOW".


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## Kathyy (Feb 22, 2010)

Well doing something now is a good thing, the tank looks nicer with no algae! I had a pretty good idea why that green ghost was back there and CB hasn't been a plague for me for a long time so I let it stay for a while. The CB used to grow on the back of the overflow box where there was good light and no water flow and the tank sure looked better when I took the box out and cleaned it.


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## Blacktetra (Mar 19, 2015)

The black electrical tape killed off one of the patches of BGA. It didn't get enough light to survive. The second spot I both covered and dosed with H2O2, it died, but now I have a touch up on the surface, above the gravel. More H2O2 to the rescue I suppose. Just wanted to share that the tape helped.


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