[Coral-List] Water quality parameters?

[Julian Sprung]

Dear Jade,

The values will quickly become 0 mg/L without any special effort on your part as the soft corals assimilate the supplied nitrogen, or denitrification within the sandbed processes it. The supply water does not have to be free of ammonia or nitrate. You should be able to see this by taking measurements from the bulk water in the tank. If there is any measurable ammonia or nitrate, then the exchange with new water is at a really high rate, or you have no sandbed.

To avoid promoting excess algae in the exhibit, it would be best to run the water over illuminated turf scrubbers or through a sump/refugium with illuminated algae (such as Chaetomorpha spiralis). That would strip out the ammonia/nitrate from the new water prior to it entering the tank. The algae would have to be harvested to promote rapid growth and assimilation of nutrients, and export the assimilated nutrients.

You can play around with the amount of algae needed to achieve the best result. The supply of ammonia should make the soft corals grow well, and limiting it would slow them down.

Julian

> ----------
> From: 	coral-list-bounces at coral.aoml.noaa.gov on behalf of Jade Maggs
> Sent: 	Tuesday, January 10, 2006 5:46 AM
> To: 	Coral List Server
> Subject: 	[Coral-List] Water quality parameters?
> 
> I work in a public aquarium and I look after a coral exhibit which is predominantly soft corals. The total volume is around 20 cubes half of which is the sump and Rk2 skimmer. The configuration is semi-open, with make up water from the sea being added continuously. The problem I have is that our incoming water has ammonia up to around 0.2 mg/l but more like 0.1 mg/l. The water also passes through a sand filter between sump and exhibit and readings have indicated the sand filter resulting in a slight drop in ammonia and nitrite and a rise in nitrates from 3.5 to 4.5 mg/l. Are these values too high, just acceptable or completely acceptable. The nitrite is around 0.024 mg/l. I know everything should be around 0 mg/l, but how critical are my values. 
> 
> My solution is to turn the make-up to a trickle and pile in the live rock and create a refugium in the sump. My problem then is to chill the water as the make-up keeps it within an acceptable range. 
> 
> Any help advice would be much appreciated.
> Jade Maggs
> Aquarist
> uShaka Marine World
> 083 515 1079
> _______________________________________________
> Coral-List mailing list
> Coral-List at coral.aoml.noaa.gov
> http://coral.aoml.noaa.gov/mailman/listinfo/coral-list
> 
>