# Still struggling with PFS turning black! 55G Lake Tang Setup



## Ensorcelled (Mar 1, 2011)

So just as my subject title says, I'm still struggling with this. I previously made a topic over it and thought I had come to a fix, but it turns out I have not. I had 4 "deco rocks" in the tank that I have since removed in an attempt to fix the problem along with removing a good bit of sand. What else can I do to prevent this? I have no problems whatsoever with sand turning black in my 75G Malawi tank, but I can't stop it from happening in my tang tank?

If it helps, the filtration is a Single Eheim 2217 w/spraybar. Do I need to add a powerhead aiming toward the bottom of the tank or is this going to be too much current for my guys? I have a spare Koralia 750 (750gph) laying around that I'm ready to put to use, but am scared it will be too much. I also plan to leave the tank with just the escargot shells because the other rocks just made the problem worse...

The tank is stocked with Ornatus, Calvus, and Multies.

Thanks in advance!


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## CrypticLifeStyle (Dec 14, 2009)

Your going to be asked the following i'm sure so here they are. What are your water parameters? How old is the tank ( as in being setup with water )? Can you provide a pic. of this ? What is your weekly maintenance schedule. Also a 2217 is something i'd put on a 29g , i would say you dont have enough filtration no matter how much media is stuffed in that thing.


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## smitty814 (Sep 27, 2012)

You need to stir the sand just before water change. You could put some plants in and malaysian mystery snails. Both of these will help stir your sand. I have found that in buying plants you automatically get the snails.


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## CrypticLifeStyle (Dec 14, 2009)

smitty814 said:


> You need to stir the sand just before water change. You could put some plants in and malaysian mystery snails. Both of these will help stir your sand. I have found that in buying plants you automatically get the snails.


True that, unless you dip them. Not to mention other critters which i'm learning all about at the moment. Hydra being one of them thats fascinating me.


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## Ensorcelled (Mar 1, 2011)

CrypticLifeStyle said:


> Your going to be asked the following i'm sure so here they are. What are your water parameters? How old is the tank ( as in being setup with water )? Can you provide a pic. of this ? What is your weekly maintenance schedule. Also a 2217 is something i'd put on a 29g , i would say you dont have enough filtration no matter how much media is stuffed in that thing.


Paramters are all in check. Tank has been up and running for little over 6 months. Unfortunately, I do not have a picture to provide unless it happens again. I do 60-70% water changes every week. The 2217 has been handling the tank very well alone but you might be right. I have a spare AC110 im thinking about throwing on this tank for extra circulation and filtration but am hesitant because the tank is in my bedroom. I might throw it on there anyway and give it a shot because I think my issue is lack of water flow from just the 2217 by itself.

Plants are a thought I never gave. Some good points here.


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## CrypticLifeStyle (Dec 14, 2009)

How deep is the substrate? Are you doing weekly vacuums? Pool filter sand is mainly silica sand, and between that, and the color black chances are it's diatoms. You can limit the flow on the 110 if you want. 
Plants, and africans i cant really comment on, i'm not a african guy, and dont really pay much attention to african stuff so maybe someone else can help make recommendations if you choose to go that route. What is in the 2217 for media?


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## Ensorcelled (Mar 1, 2011)

CrypticLifeStyle said:


> How deep is the substrate? Are you doing weekly vacuums? Pool filter sand is mainly silica sand, and between that, and the color black chances are it's diatoms. You can limit the flow on the 110 if you want.
> Plants, and africans i cant really comment on, i'm not a african guy, and dont really pay much attention to african stuff so maybe someone else can help make recommendations if you choose to go that route. What is in the 2217 for media?


Substrate was significantly reduced down to about 1-1/2" to help with the problem. Weekly vacuums are done every week. Definitely not diatoms as when I disturb the sand that is discolored I get a horrible rotten eggs/death smell...which is synonymous with the problem.

I'm really starting to think its a lack of flow in the tank. Hopefully someone who has had this problem before chimes in to confirm my suspicion or not...really starting to get frustrated over here. :x


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## CrypticLifeStyle (Dec 14, 2009)

Well if you do good weekly vacuums you can have a deeper substrate bed. My tanks are a good 3", and never a issue. Lets say its not diatoms, option 2 is then algae. Which needs a food source of more then needed, or something lacking to grapple onto things like they have with you. I'd cut down on feeding, do more of a deep vacuum, and cut down the light schedule for a little bit. You want to deprive it of it's food source. Lack of flow is a good point. A 2217 is pretty small for a 55g. A powerhead would definitely help.


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## nodima (Oct 3, 2002)

Is the surface of the sand changing to black, or is it changing from the bottom up?

The approach to correct would be different for these scenarios. If it is surface, it could be algae like growth - could change bulbs/duration etc. Are you using the same sand in the Malawi tank, or is it different?

What are the differences between each tank? Same lights, same equipment, same placement in room, how about additives etc? Does the tank get *any* sunlight?

It could be something in the batch of sand - if it is PFS, short money to replace, a bit of a hassle, but short money.


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## smitty814 (Sep 27, 2012)

The rotten egg smell is the release of nitrogen gas. Anerobic bacteria is using the oxygen molecule in nitrate converting it to nitrogen. You need to stir the sand and do water changes. Or you could leave it alone. Except for the smell it's completely harmless. :fish:


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## cichlid-gal (Apr 27, 2012)

The only time I have had a black spot in my sand is when something has gotten "buried" in the sand...a heavy piece of broken plant root, an algae tablet...those caused a dark spot in the sand. I removed all the dark sand and put clean sand in its place. The spots didn't return. Is the black sand always in one location in the tank or is it found all over the tank? When you clean it are you removing the black sand or just stirring it around? I would definately recommend removing ALL black sand.

If you only have the black spot in one location in the tank I would remove everything from that location including the original sand (use a divider and get the fish out of the way), turn off your filters, scoop out the bad sand, use a big water bottle filled with sand to refill (after it tops off with water and you are near the bottom of the tank with the bottle, turn it upside down and let the sand fall into place...the bottle will capture any leftover sand sediment...remove bottle with sediment water... repeat as necessary).

If you have the black sand all over your tank I would take everything out, remove all the sand, replace with new and start over making sure your maintanence includes weekly stirring of the sand bed. Hopefully that will solve the problem.

Good luck.


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## smitty814 (Sep 27, 2012)

No, really....replacing the sand without figuring out the cause is useless.


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## Ensorcelled (Mar 1, 2011)

smitty814 said:


> The rotten egg smell is the release of nitrogen gas. Anerobic bacteria is using the oxygen molecule in nitrate converting it to nitrogen. You need to stir the sand and do water changes. Or you could leave it alone. Except for the smell it's completely harmless. :fish:


Exactly this. The smell was so horrible it stunk up my bedroom for a good hour!



cichlid-gal said:


> The only time I have had a black spot in my sand is when something has gotten "buried" in the sand...a heavy piece of broken plant root, an algae tablet...those caused a dark spot in the sand. I removed all the dark sand and put clean sand in its place. The spots didn't return. Is the black sand always in one location in the tank or is it found all over the tank? When you clean it are you removing the black sand or just stirring it around? I would definately recommend removing ALL black sand.
> 
> If you only have the black spot in one location in the tank I would remove everything from that location including the original sand (use a divider and get the fish out of the way), turn off your filters, scoop out the bad sand, use a big water bottle filled with sand to refill (after it tops off with water and you are near the bottom of the tank with the bottle, turn it upside down and let the sand fall into place...the bottle will capture any leftover sand sediment...remove bottle with sediment water... repeat as necessary).
> 
> ...


It appears all around the tank starting from the bottom of the sandbed and showing up towards the top. I had rock decorations in there up until recently that when I would move them out of the way, the sand that was under them was completely black and then I could smell the horribleness. I have not been removing the sand but have instead been stirring it around.

I'm just baffled at why I'm having this problem with this tank when my malawi tank with Eco-Complete substrate has never given me any problems whatsoever and I don't stir their sand much at all unless I'm completely re-doing their decorations...and even when I do stir their sand it isn't black and does not stink when I do. :-?


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## nodima (Oct 3, 2002)

sounds like you may have too deep a sand bed. I try to aim for an inch or less of sand. Much harder for anerobic pockets to develop. And while sand is less work than gravel, it does still need to be stirred or vacuumed at least every couple of water changes, especially if it is deep.


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## Ensorcelled (Mar 1, 2011)

Well in another attempt to fix this issue, I have removed more sand from the tank. I have also added back my rock decorations but modified them by cutting "holes" in them so the fish can get in them etc and have water flowing through there as a way to eliminate a dead "no flow" zone underneath. I have also added my spare AC110 to the tank for added filtration and flow. I hope this helps because I'm getting really annoyed! :roll:


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## smitty814 (Sep 27, 2012)

How about some pictures. If you take out all the sand....black sand problem solved. :drooling:


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## Ensorcelled (Mar 1, 2011)

smitty814 said:


> How about some pictures. If you take out all the sand....black sand problem solved. :drooling:


I'll snap some later today. I don't think my multies would be too happy if I took all their happy fun time spitting sand away!


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## BillD (May 17, 2005)

Sounds like you have anaerobic pockets which do turn black and give off the sulphury smell when disturbed. Stirring the bed regularly is the answer, either manually or with the use of Malaysian Trumpet snails.


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