Nitrate problems please help me

I currently have a 40 gallon acrylic tank which was started at the end of october of 2010. It has 1 white t5 bulb and 1 blue bulb. Current temp is at 76 degrees. I have 25 to 35 lbs of cured live rock (under a bit for what i should have from the typical 1 to 2 lbs). i have a few soft corals but nothing out of control or overstock wise. Some leather corals and frogspawn and zoo's. I have one clown fish and a blue hippo tang (very small right now) which are the only fish. i have 4 snails 2 turbo and 2 smaller ones and 3 red legged hermit crabs and 1 emerald crab. 2 power heads for water flow. i have a eheim canister filter with media and eheim substrat. i have a octopuss skimmer rated for a 80 gallon tank. My nitrates are at 20 ppm and i did a 50% water change. the nitrates then went down for about a week to 10 ppm. They went right back up to 20 ppm again. i dont understand why. The corals seem to be affected slightly but my fish seem just fine. i run my lights for about 10 hours to 14 hours aday (going to cut them back) all other levels are fine ammonia is at 0 so are nitrites phosphates are at .25 calcuim is at 520 and ph is anywhere between 7.8 to 8.0 never seems to improve either not sure why. i have accounted for all livestock nothing has died. i do use RO water and it has been tested to be just fine level wise. what can be causing my NITRATES???? i really need help here im at a loss for words or ideas i have done alot of research and can come up with no solution so far. Thanks for any advice in advance

 

Hello and Welcome,

How often are you cleaning the canister ? Have you thought of using other media in it?

Nitrates of 20 are not that bad considering you have tang in the tank. Fish, soft corals and a lot of LPS do fine at that level.

How often are you feeding and what are you feeding?

 

I normally only change it when i do a water change. my main concern is that after a 50 % change it went right back to 20 ppm again a week or less later. i have filters for ammonia and phosphates in the canister filter and filter floss and media to help filter.

 

We did over 80 gallons of water changes in are 90 gallon tank over a weeks period and are nitrates didn't go down at all. Still at 30-40ppm.

I'm not to sure how canister filters work, but we use a fuge with chaeto and mangroves. Mangroves seem to help a lot, but they need to have roots/be growing.

How well is your skimmer working? Is the water in the collection cup dark in color or somewhat clear still?

 

Just thought I'd repeat that LOL.

 

Do you/Did you have snails in your canister filter- even little ones? What are you running in the canister for total filtration?

BTW, you can change water every day, if the canister is full of snail or waste- you have done nothing but basically top off the water. Remember - BIO filtration is why canisters are so popular in the fw aquarium would, well that bio load is 100 times greater in a marine tank. This is why many "reefers" do not use them- I do on my 29, but I clean it out every 2 weeks- I also run a good skimmer on this tank. I only use the canister for mechanical filtration- nothing more.

 

Your tank is still quite young. How long did you cycle it before adding livestock. The bacteria could still be trying to catch up at only 6 weeks old. Phosphates are alittle high. I know this is not optimum but I have heard and read where others have hung Phosban(GFO) and Carbon(GAC) in their cannisters and were successful.

 

I just added my fish a couple days ago. My skimmer is working well pulling a brownish water out the nitrates just seem to stay at 20 ppm they don't go up past that but they don't go down unless I do a water change but shoot right back to 20

 

if you gave me your tank as it stands today
this is what I would do with it.

next week, remove and throw away 25% of whatever you have in the cannister
the week after remove and throw away another 25%
week 3 - remove and throw away another 25%
week 4 - remove and throw away whats left
rinse the unit out fully and then run it empty,for flow if you want (but flush it out each week)
or use it for carbon or other chemical media should you need or wish to (and flush it out each week)

do 20% water changes each week in the mean time

adding a bit more base rock, would not be a bad idea, but your bioload does not seem overly high and as such I believe your current rock could handle it in terms of being adequate real estate for the bacteria required to process your wastes in that system

in 5 weeks time- I predict you will probably say "I was a bit nervous about taking my filter apart slowly but my nitrates are below 10 now or even possibly lower."

no promises on how low they will be

but IMHO and due to my own previous experiences They will be lower.


Steve

 

Yes what Steve said!!!