Tropical Fish Forums

Jimbob · Regulars Joined: 27 Feb 2004 Location: London, England

I have noticed that over the last six weeks or so the nitrate levels in my 68 Ltr marine tank have started edging up towards 10ppm. To counter this I have upgraded the protein skimmer from a Berlin airlift to a Prizm Delux and increased the water changes from 10% to 20% a week.

My question is whether this is going to be sufficient in the medium/long term or should I be considering other measures to keep the nitrates down?

Presently I have, in a 68 Ltr tank, one:

Cleaner shrimp
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sirreal63 · Advisors Joined: 21 Feb 2004 Location: Meadowlakes, TX

Increase the frequency of the filter cleanings, remove the bioballs, the bale, the filter wool and the ceramic. These tend to accumulate nitrates and release them back into the water column. In your cannister filter run carbon and change it out every other week and clean the filter completely. Cannisters work great for freshwater but can be a problem in salt. I only run carbon, phosban and sometimes nitrate absorbing resins in mine. My system has been running a few years now and my nitrates remain undetectable.

You upgraded to a skimmer that is no better than the one you already had, maybe even less than the one you had. Your rock and skimmer will handle the bulk of your filtration needs. Raising your salinity to 1.025 will help in skimming. Water changes will go a long ways towards reducing your nitrates and keeping the cannister filter clean will prevent their rise and your schedule and amount of change is a good one, keep doing that.

Don't add any other fish as your bio-load is maxed out in the tank.
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Out on the road today...I saw a DeadHead sticker on a Cadillac...
Jack
110 Gallon DSA Pentagon

Jimbob · Regulars Joined: 27 Feb 2004 Location: London, England

Thanks for your comments Jack, can I remove the contents of the cannister in one go or is it better to take them out over a period of time? (I am thinking about potential spikes/mini-cycle).
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Stand and deliver... your lupins or your life

FloridaBoy · Moderators Joined: 04 Jul 2004

Wow, that's a refreshing question! Nice to see someone providing all the info up front.
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Keepin' marines happy for 25 years

sirreal63 · Advisors Joined: 21 Feb 2004 Location: Meadowlakes, TX

I would do a little every other week.
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Out on the road today...I saw a DeadHead sticker on a Cadillac...
Jack
110 Gallon DSA Pentagon

Jimbob · Regulars Joined: 27 Feb 2004 Location: London, England

Update from my last post, the enhanced cleaning regime and new skimmer seem to be paying off. Nitrates are back down to 5ppm and I aim to get this down even further.

I have been slowly removing the media from the canister filter and I am being very cautious with the removal rate. I know it is the right thing to do but after over twenty years of maintaining freshwater systems I am feeling more than a bit nervous about it.
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Stand and deliver... your lupins or your life

sirreal63 · Advisors Joined: 21 Feb 2004 Location: Meadowlakes, TX

I understand your trepidation. It is the right thing to do though. Saltwater is greatly different from fresh. The water chemistry is much more exacting and complicated. Stay on the path and where your nitrates are now is perfectly fine.
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Out on the road today...I saw a DeadHead sticker on a Cadillac...
Jack
110 Gallon DSA Pentagon