Advice for a dying reef tank..

[oysterboy]

Hi everyone, first post here in hope of helping me solve some problems I've had with my Reef tank over the last six months...

So some details :
I've had a reef tank set up now for around 3 years.
Its 65gal tank with overflow into a 20 gal sump/refugium with skimmer. Top off with RO/DI water and run a chiller to keep temp around 79f and run water through a UV steriliser. Have a 1 1/2 inch bed of sand and plenty of live rock taking up approx 25% of the volume of the tank. Have 2 20K metal halite lights over tank. I normally replace saltwater with about 15 gals every 3 weeks and run a mechanical filter with carbon for a week once a month.

Livestock : 2 clowns , yellow tang, orange tipped bristletooth tang, sailfin tang, regal tang, kliens butterfly, 6 chromis, blue spot Naso tang. Fire shrimp & lots of hermits and turbos. All fish are healthy and happy.

Corals : I have a range of soft corals including a leather coral & finger coral but have been slowly loosing all my other corals including bubble corals, brain coral, green star polyps and most recently a large colony of Clavularia polyps...

Problem : I've tested all my water regularly and the only problem seems to be my nitrate which is currently above 20ppm possibly around 30-40ppm. For months now I've tried to bring the nitrates down with no success using media and have done water changes as much as 80% which have got it down to around 5ppm but within a few days the nitrates start creeping up again.

So I figured that my problem is overstocking. My Naso Tang in particular is getting big 7-8 inches long. I feed dry food and seaweed once a day so I don't think their being overfeed just too many fish..

Im trying to figure out what's causing my problem and other than overstocking Im wondering if my live rock is still live. A while back I had a breakout of aiptasia and ended up removing the rock to a black tank for several weeks scrubbing them to kill of the aiptasia. However I forgot to keep the water heated and wonder if I killed off my rock and in doing so the biological filtratration process... The rock is covered with plenty of good looking coralline algae but not anything else.. Could I have killed off my live rock???

Any help or suggestions would be greatly appreciated as Im at a loss to figure out where to go...

thanks

[Ninong]

Hi oysterboy,

...wonder if I killed off my rock and in doing so the biological filtratration process...

No, you didn't permanently kill off "the biological filtration" process because the beneficial bacteria would rapidly recolonize the live rock after it was returned to the tank. You may have killed off a lot of the other life in and on the live rock and maybe it's some of this life inside the live rock that has not yet completed the process of dying off.

How long ago did you return the live rock to the aquarium? Has your nitrate been high ever since then?

Yes, your aquarium is overstocked in tangs. Personally, I think it's too small for any of those tangs but you might be able to keep just the one yellow tang. The naso tang and the sailfin tang in particular require a tank that is much, much larger than yours.

There are a lot of other fish that would be better for your tank. I wouldn't choose anything with an adult size above 4" if I were you. Your tank just isn't large enough for big fish.

[oysterboy]

Thanks for the advice.

I think I cleaned up the rock about a year ago. I noticed the nitrates rising around Nov last year. There was a period where I forgot to clean the sump much and the sock had started to clog up with detrus etc so that may have started the problem. Since then I've been better at cleaning it when I do my water change so i don't think that is contributing any more.

Here's my plan - let me know what you think.

I need to find a bigger tank as a fish only tank and run it off my canister filter. I'll relocate all my fish to that tank. Then I'll empty my display reef tank and refill with all new salt water - (I collect mine from the pacific). I might replace/ add some new live rock to help spawn some new life onto the existing live rock. Then without fish in the reef tank i'll let everything settle down again and when nitrates seem at 0 try introducing some new corals.. If things stay settled I may add the yellow tang back perhaps the bristletooth... but leave the others in the fish only tank. I've offered up the Naso the Academy of sciences for their 212,000 gal tank - I guess he would have more room there if they want him!

Here are some pics of my tank taken in March this year:

[Ninong]

...all new salt water - (I collect mine from the pacific).

Exactly where do you collect it? How do you collect it? How far from shore, etc.?

What do you do with this seawater after you collect it? Are you using it immediately or storing it? If you are storing it, exactly how and for how long before using it? Are you allowing time for all of the plankton to die off first?

Obviously there are issues will using water too close to the coast in California. Things like oil spills for instance. I lived in the Bay Area and the Monterey-Big Sur area for 21 years and I can tell you that I have come across globs of oil on the beaches everywhere I went, from Stinson Beach all the way down to below Big Sur. I never went more than about 75 miles south of Big Sur or 50 miles north of San Francisco.

Using natural seawater can be very tricky. The Monterey Bay Aquarium uses it unfiltered at night only and only for their largest display. The rest of the displays use filtered natural seawater and even the largest display uses filtered natural seawater during the daytime.

At the very least, the natural seawater that you collect should be stored in a covered container for a week to allow all of the plankton to die off and settle to the bottom. Then the water should be siphoned without disturbing the sediment in the bottom of the container. And that won't have any effect on potential pollutants in the water.

What are your test results on the natural seawater? Any nitrate readings?

I've offered up the Naso the Academy of sciences for their 212,000 gal tank - I guess he would have more room there if they want him!

Did they respond?

Here are some pics of my tank taken in March this year:

As you can see from that third photo, your Naso has outgrown your tank, but you already know that.

[oysterboy]

Exactly where do you collect it? How do you collect it? How far from shore, etc.?

At the very least, the natural seawater that you collect should be stored in a covered container for a week to allow all of the plankton to die off and settle to the bottom. Then the water should be siphoned without disturbing the sediment in the bottom of the container. And that won't have any effect on potential pollutants in the water.

What are your test results on the natural seawater? Any nitrate readings?

Did they respond?

As you can see from that third photo, your Naso has outgrown your tank, but you already know that.

yes Im only to well aware to the oil spills and pollution around the bay. I would never eat fish caught in the bay.

I collect my water from the shore at Bolinas ( would love to have a boat but alas). I would never collect in or near the bay itself but at Bolinas there is a good flow of water throught the channel relively few boats and its next to duxbury reef so I figured its probably a fairly good bet that the water is not too poluted. The location I collect has plenty of sealife including anemones and starfish and due to the flow of water there is quite a lot of natural skimming going on. Its also about the only place I can drive up to.

I collect it the hard way with a bucket over the edge of the seawall and transfer it into a 45 gal Brute container in my car. I check the water in a glass jar to make sure I can see microorganisms darting around and try to collect near high tide. Usually Im able to collect about 70 gals at a time this way.

I test the water and the nitrates are 0. It sits in my basement in the brute containers with lids and no light to settle for several weeks as you suggested. I then carefully take water from the top using a 2 gal bucket as I need it for changes. I throw away the bottom couple of inches with any sediment.

Haven't had a response yet from the Academy - don't really want to part with him but I know he needs more space than I have currently.

When you say the monterey bay aquarium filters during the day - what type of filtering do they do?

[Ninong]

When you say the monterey bay aquarium filters during the day - what type of filtering do they do?

See page 5, Seawater System.

The water you are collecting in Bolinas is not necessarily safe just because it looks safe. It's subject to all the pollution from ships going in and out of SF Bay, to say nothing of major oil spills that happen from time to time.

I'm not saying that's your problem, I'm just saying that natural seawater can be tricky if you collect it yourself. The natural seawater that Scripps gives away FREE to hobbyists is filtered first. I don't know if the Seattle Aquarium still sells filtered natural seawater for 5 cents a gallon but they used to when they first opened.

The water that the Monaco Aquarium uses is filtered natural seawater from the Mediterranean.

The new, gigantic Georgia Aquarium in Atlanta uses artificial seawater, which must cost them a fortune. They used up 1.5 million pounds of Instant Ocean salt mix to make the saltwater for their initial fill.

[Ninong]

Bolinas was hit hard by the 58,000 gallons of heavy-duty bunker fuel oil that spilled into SF Bay in November 2007. The Coast Guard said then that the effects of that oil spill would be felt for years.




More photos of oil encrusted beaches from south of Pacifica to north of Bolinas.

[oysterboy]

Free filtered water - that would be cool - maybe i should just move to San Diego
So beyond the usual water tests for calcium nitrates etc that I would normally carry out how could I test for pollutants in the water..?

Incidently I started getting my nitrate problems before I collected from the sea. My lfs closed due to the recession in Feb so I decided to try collecting it myself. Would still like to know if its safe however...

[Ninong]

You can't test for pollutants; that would be way too expensive. However, a lab that did test the water just offshore in Southern California for pollutants found a very high level of petroleum products. They said the most likely culprit was not oil spills as much as fallout from onshore oil refineries and chemical plants. Note that the natural seawater the Monterey Bay Aquarium uses is drawn from a pipe that extends 980-ft out from the shore and 55-ft deep.

What you can test is salinity just to make sure it's not too far off from what you have in your tank. Salinity can vary, especially following heavy rains. It won't vary much at all if you're drawing your water from 55-ft deep and 980-ft offshore. If you want to test for calcium and alkalinity, go right ahead. Alkalinity should be right around 7 dKH and calcium will probably be around 380 ppm, a little lower than average NSW calcium. Obviously nitrate should be zero.



P.S. -- Salinity averages 35 ppt near tropical reefs but it falls off as you get farther away from the equator. Your salinity will probably be around 33 ppt.

[Parrothead]

Ninong.

Another key element in collecting natural seawater on you own is simply this, I've owned a boat or three in my life and everyone of them had their own little leaks, not just in but out, you can find "pure" water offshore, but odds are you are going to screw it up when you bring it on board from you own vessel caused by fuel or oil leaks around your boat, hate to say it but the Fla Keys are suffering from just the same thing. Just my humble thoughts

Robert

[Ninong]

State awards funds to help protect Bolinas Lagoon from spills

Workers who tried valiantly to protect Bolinas Lagoon after the Cosco Busan oil spill learned a valuable lesson: They needed more training and equipment.

This week, a state agency provided money to help.

Bolinas Lagoon was heavily polluted in November 2007 from the Cosco Busan oil spill.