hello mate, just a thought, have you checked the params on ya ro water before you add it to tank? could be ya getting dodgy ro

__________________
WHO'S YA DADDY

Hi Telboy how u doing!!! No I haven't will do! Darnit!!! This i'll put me straight on the dogey testing kit! Do u know where i could fine some info on RO units???

Sorry Telboy Dodgy

dodgy=in my short experience in keeping marine i have found that the quality of ro differs! some dubious lfs have been known to sell half ro/half dechlorinated tap water mix...it all depends on the stages they put it through! ie a 2 stage is nowhere near as good as a 5 stage or do you make ya own ro?as for info just google "ro units"

__________________
WHO'S YA DADDY

Just some thoughts:

Whilst I have heard of live rock being put in canisters, i'm a little dubious of it myself but I see no reason why it shouldn't work, I am a little concerned about the use of alfagrog I know it has an open structure an all that great for bacteria I just think the structures maybe a little to open and as such will not have anaerobic bacteria which is one iof the ways live rock consumes nitrate. So the alfargog is basically my first concern this maybe your nitrate factory.

Secondly you haven't given details of the in tank water turn over rate as a bare minimum it should be 10 times the tank volume per hour however with a nitrate problem I would look at upping this to in the region of 40-50 times per hour. This will prevent settlement of detritus or at the very least reduce it considerably keeping the debris in the water column enabling the skimmer to get shot of it.

In addition do you have space for a sump tank? If so consider adding a miracle mud filter these have to be lit 24 hours a day but flourescents are sufficient this will consume huge quanitities of nitrate as well as providing a continuous trickle of plankton for the aquarium.

How much live rock do you have? Is there any tuffa or ocean rock in there?

The only rock you should use is live rock anything else to put it bluntly is taking up valuable water volume so get rid, there is a school of thought that tuffa rock will actually produce nitrate pressumably due to the open structure not becoming anaerobic and therefore harbouring nitrate producing bacteria.

To give an indication of stocking I have a 255 litre tank with 6 green chromis 1 fox face 1 coral beauty 2 banggai cardinals 2 black percs and 1 pyjamma wrasse my nitrate level peaks at about 5 ppm before a partial water change.

The tank is filtered by a DSB and algae refugium combined lit 24 hours a day and with 30 kilos of live rock. I also have a delted mce300 skimmer not nearly as powerful as your skimmer. Plus an eheim 2215 that is empty and used only to power a UV sterilizer. The only artificial filtration I use is the skimmer everything else utilises natural methods.

The tank volume is turned over approximately 25 times per hour I intend to increase this by an approx additional 5,000 litres per hour as I have an unexplained algae problem and I suspect it is down to insufficient water flow as phosphates and nitrates are very low having said that my grazing pressure is not very high I only have about 6 black foot turbos I have nothing that will eat hair algae!!!!!!!!!!

Incidentally I feed 2-3 cubes of frozen food per day in the morning and evening.

My main concern is that the tangs may ultimately outgrow your tank otherwise in my opinion I do not think you are over stocked at this time but as the fish grow this may become a problem to fix it add a substantial sump. This won't get around the size issue with the tangs but would help with tank stability and dilution of organics including nitrate and phosphate.

Sorry went on a bit hope you find some of this useful.

__________________
Alan

Thweeerp!

One more thing www.stm-shop.com sell a product called nitrate minus it is apparently very effective at reducing nitrates in marine tanks with effective skimming not sure how it works but it is reef safe its called something like a to z nitrate minus or nitrate reductor. I think it is bacteria based.

__________________
Alan

Thweeerp!

dont expect miracles with this water change , as you are only changing 1/6th of the water so your nitrates will only drop by about 17% at the most proberly a lot less than that because your fish are still doing what every living creature does eat and cr-p ,your best bet is still to buy some nitrate reducer and continue to do water changes . ( a lot more frequent than you are currently doing.)

hi just a quick thought you could try adding some cheeto that would help lower the nitrates i believe not an instant cure but helps in the long term

Hi guys!
Haven't got the room 4 a sump! its only a 1230xl from aqua one. Changed 50ltrs of water didn't change on monday. Doing the same thurs/fri same again!!! over a month??? My parts haven't still arrived from aqua medic!!! B******s!!! To get the nitarateductor up and running!!!!! Cut the feeding down 2 flakes in a morning and nori at 5pm. then every other day 1 cube mixed with cyclop-eeze?????

Hi Guys!!!!
The cannister filter I've got is a new one from aqua-one with the uv. If that helps??????