silicate problems from Southdown sand?

[fishy all the time]

I have a 210 gallon reef tank that has been up and running for about 5 years. I have upgraded tank sizes through the years but have changed nothing else. I conside it a established tank with no problems. I am worried though because the tank seems to not being doing to well. All water chemistries are fine. Nothing ever changes. The temp is 77.8 and might creep up to 78 during the day. Ammonia is zero, nitrites are zero, nitrates are 10, pH is 8.2, and salinity is normal. A few weeks ago we added 3 cardinal fish and then a week later added 4 more. All of them died. I added a clown goby and that is fine. Most of the other fish are original and have been through all the diffent sized tanks. About 3 days ago I noticed my gold bar maroon clown had stopped eating. Eveything else was fine ( no other things were noted wrong) Then it died. My frogspawn, which has been growing for years and is hugh, just seemed to die overnight. It is pure white except for one branch that is closed up tight. I checked the tank for copper and phosphates and even through in a poly filter for kicks. Normal. My worries are though now are from the Southdown sand. My lfs owner and his wife often go out to eat with my boyfriend and I. He always stears us in the right direction. He keeps telling u though that there are silicates in this particular sand. The would also explain why we can grow coraline like mad. Since we have switched to this particular tank we have had no growth. My lfs guy has told me that is because the silicates have broke down. He thinks this has released toxins into the water. Can anybody help me with this or have any ideas. I have not tested for silicates since I dont have a test. I would have to order one from somewhere. Thanks for the help, I am just worried since we have never had any tank problems. Sorry this is so long.

 

[bang guy]

A few comments:
Southdown is very low in Silicates.
Coralline does not use Silicates.
Do you have any Leather Corals?
How much sand do you have?
How often & how much water do you change?
What brand of salt do you use?
What do you use for your fresh water topoff?
What are your levels of Magnesium, Calcium, and Alkalinity.
What kind of Cardinal? Were they wild caught?

 

[fishy all the time]

We also have this brown film on the sand.

 

[fishy all the time]

to answer your questions...
There are several leather corals that we have.
I think we have 200 pounds...it works out to between 4 and 5 inches.
We to a water change once a month but sometimes we let it go longer. It has been about a month now. I guess we change about 10 gallons.
We use instant ocean salt and that is all we have used.
We have a auto top of that is run from the cold water. It may seem silly that we use tap water but it is what has worked best for us. We use to use ro water but that tank always looked sick. We switched to tap water years ago and have not had problems.
Calcium, and alk are normal and I have never tested for magnesium. Calcium was between 300 and 400. I can remember what the alk was.
They were banghei cardinals (sorry about the spellng)
I am not sure if they were wild

 

[jscarb2]

sound to me like it was something you added!if it just started after adding the fish and it is a 5 year old setup.i have never had a problem with southdown.just my 2 cents

 

[bang guy]

Tap water can change with the seasons so that's a possibility. Leathers produce defensive toxins that can accumulate and affect other corals.
I've heard many many complaints now about wild caught Banggai Cardinals dying for no apparent reason. I'd recommend spending the extra $$ and get Captive Bred if you want Banggai.
I'm also going to recommend a 40 gallon water change and see if that perks things up. I strongly suggest using RO/DI water for mixing with the salt because most tap water is extrordinarily high in silicates and a large water change is going to give you a nice big diatom bloom if you use tap water.
My gut tells me that your Maroon contracted whatever the Banggai had. Mostly just because of the timing but no real proof.

 

[overanalyzer]

Originally posted by Bang Guy
My gut tells me that your Maroon contracted whatever the Banggai had. Mostly just because of the timing but no real proof.
My thought too - unless you put the new fish in a Q- Tank first.
Also a 10 gallon water change on a 210 gallon tank is not even a 5% water change so if you have something building inyour tank you are not dilluting the toxin very much each month.
Good luck!

 

[beaslbob]

First of all you may very well have had some sort of infection or parasite the attacked your fish.
Are you sure of your ph and has it dropped? if so you may be having excess carbon dioxide.
Corraline needs calcium. Have you checked that?
I seriously doubt the silicates are the problem.
With the brown on the sand and the reduced corraline you have reduced you total plant life in this much larger system. As a result you have much less plant life to consume the carbon dioxide, and nutrients such as the phosphates, ammonia and nitrates. I would first take care of the plant life before adding other life. My recommendation is to find out how to get the corraline reestablished.

 

[bigmac]

So the 210 has been setup for 5 years with a deep sand bed? Have you tested for nitrates? What kind of salt mix do you use?...

 

[bang guy]

Hey Mac,
He stated the Nitrates are 10 (marginal IMO but not fatal) and uses IO.
Just pointing it out so you don't have to read the whole thread.
FYI Fishy - BigMac is a lot more knowledgeable about the Coral aspect of reefing than I am.

 

[fishy all the time]

I will attatch a picture of my clown in his favorite home. I guess I am just bummed since he was my original fish. Maybe he was just old.
As for the pH, I am sure it is 8.2. I will check it again in the morning when the lights come on. If I still get the same reading I will have my lfs test it.
As for the cardinals. I never found any bodies but I am sure they died since I never could get them to eat much. I am sure they were eaten before I found them. I know there are some big worms in there. In fact something burrows into my leathers everyone in a while. I look at them close and cut the bad spot out but I never find anything. I suppose that could be a reaon for the release in toxins. I have not done that in a long time though.
I guess I will just have to watch the tank close for a while. My frog spawn has gone through a "stage" like this before and bounced back. Hopefully the same thing will happen this time.
Thanks again for all of your help.

 

[bang guy]

What were you feeding the Banggai?

 

[fishy all the time]

I tried all the different frozen food that I had. Brine, mysis shrimp, marine cusine, and emerald entree. I even tried flake food. I tried adding garlic to the frozen food as well.