Nitrate Problem... Old Tank Syndrome?

[JXE]

Hello,

I am hoping you can help me. I first started with salt water fish around 2000. I always focused on FOWLR and I eventually worked my way up to a 125 gal. fish only tank. By 2011 I stopped running the big tank and only had a 30 gal. with 2 clownfish. I moved into a new house and took the small tank with me. One clown died a year later and the other died maybe 2 years after that. The tank has had no fish in it for over a year and I have done little to maintain it (I basically just scraped the algae off the sides and added water to compensate for evaporation.

The tank currently contains at least 30 pounds of live rock with a mix of crushed coral and sand on the bottom. I am using a basic hang on filter and a uv sterilizer. I used to have a seaclone protein skimmer on it but I threw it out because it was not very effective.

Anyways, I decided to get back into the hobby and I thought I would test the water and get everything up to snuff before adding fish. I purchased an API saltwater master test kit. I read that certain API batches were unreliable in the past, so I tested it on a fresh new glass of mixed salt water and got zero readings on ammonia, nitrite and nitrate.

I tested the water in my tank yesterday and got the following readings:

pH: 8.4
ammonia: 0 ppm
nitrite: 0 ppm
nitrate: 160 ppm

The nitrate turned the reddest color possible on the chart... or 160 ppm!

All that time of low maintenance and no water changes has caught up with me. I found a couple of sources online that suggested a massive water change to try to cut down that nitrate number. I figured it wouldn't hurt, especially since I have no fish in there. I changed about 18 gallons of water last night.

I tested the water this morning and got the following readings:

pH: 8.4
ammonia: 0 ppm
nitrite: 2.0 ppm
nitrate: still 160 ppm... or the reddest possible color on the scale


I would be grateful for any suggestions on how I could cut down the number of nitrates. Should I keep making big water changes? Would adding a better protein skimmer at this point help? Is there something I'm not thinking about?

Thanks in advance!

[Sk8r]

Ow. Well, a total water change might help: stuff may be going into solution from rock and sand, and just tossing the affected water may help, but it may have more to give.

I've fought a similar situation resulting from a power-outage it survived--but--- And after trying every remedy in the book, I'm having results with NoPoX, and a decent Coralife 200 skimmer. It's not the fanciest skimmer, but boosted with the NoPoX, it's pulling black skimmate, and the nitrate level is going down. Another help is a ream-out of the sump, if you have a lot of crud and fluff there.

[mcgyvr]

What I would do is..
#1-Get a container large enough to hold all the live rock..Fill it with new saltwater and add the live rock and throw a powerhead in there to have some circulation..
#2-Test the water in the container and perform 100% water changes until the levels are acceptable.
#3-Ditch the old crushed coral/sand, drain the tank completely, clean it out (vinegar/water) and refill with fresh sand/new saltwater when your rock is ready again..

So basically save the live rock.. Ditch everything else and start over again.. Essentially curing the rock but starting fresh..

[Sk8r]

THat might be the shorter route, if there is no invert life you're trying to preserve. And some would still survive.

[GimpyFin]

I would do some more big water changes to get it down to a reasonable number. If you are just running a 30g with no sump, your filtration options are more limited, but a good working protein skimmer definitely helps in taking out organics before it turns into Nitrate.

How was Nitrate on an ongoing basis while you were still maintaining the tank? If it wasn't high, just keeping up on regular maintenance/water changes may be all you need. Additional methods like carbon dosing (Vodka, biopellets) can help as well long term if you have a good skimmer. It's not for everybody, but an option you could definitely look into.

[Remy LeBeau]

When your doing these water changes are you blasting the rocks with a power head or vacuuming your substrate? Did you clean the media in that HOB filter at all? If not, you might want to consider doing this. Your nitrates are so high because your tank is struggling to process all the crap within it. Remove this and you'll lower that. It's actually pretty simple.

Adding a skimmer will definitely help btw, but it's not going to make this problem go away for you. You need to nip it in the bud so to say.

[JXE]

Lots of great feedback here! Thank you!

Sk8r, I just looked into NoPoX and I'm going to pick up some for when I have this under control.

mcgyvr, I like your idea because I really have nothing to lose right now. Also, I'd be happy to get rid of the crushed coral and bring in some nice sand. I do think the substrate level is kind of high right now too so cutting back might help.

If I move all of the rock into a separate container and do full water changes until the nitrate level is good... how long could I expect something like that to take? Will the level go down on its own, or will the 100% changes be the only thing that lowers it? Can I split it into several buckets, or should I try to find one container big enough for all of it?

GimpyFin, thanks for the notes on the skimmer. I'm thinking about the Reef Octopus Classic 100 hang on skimmer. When I was maintaining the tank the nitrate readings were never high. I was changing about 5 gallons a week every week when I had fish in it and it seemed to be okay.

Remy, I cleaned the filter and I tried to get any pieces I could see when I took the water out. The stuff coming up from the substrate was very cloudy, so I'm sure there's more in there. You raised a great suggestion to blast the rock with a powerhead. I didn't think of that and I will try that today.


I will go attempt all of this great advice. I think it's time for a new skimmer either way. I'll try to blast the rocks and change a significant amount of water once or twice more. I think I can get away with permanently physically removing a good amount of the cc/sand mix too. If that isn't working I will save the rocks and get rid of all of the water/substrate and start fresh.

[mcgyvr]

Sure you could split it up into buckets..
Depending on how often you change the water, how "dirty" it is,etc.. It could take a few day to a few weeks..
Just keep dunking the rocks to/shake,etc.. to get as much of the crap off it..

And BTW.. You can use vinegar/vodka dosing instead of purchasing noPox too.. (search/read about Carbon Dosing)

really now is the perfect time to get out the bad and start as fresh as possible.. Just keep that live rock..."living"

[CStrickland]

The water changes will get out the nitrates in the water, and removing old built up crud will slow down production of more.

Are you thinking you'll do corals this time around? Fowlr tanks have a lot more wiggle room on water quality than reef tanks.

What if your water source? A lot of old school fowlr tanks use treated tap water and that can contribute nutrients and low-level contamination that make coral harder to keep.

Also, if you want to know just how high your nitrates are, you can test a sample that's half tank water and half fresh-made salt water, then double the result. That can help you keep track of what's working to lower them, since when it's at the top of the scale you don't know if it's 161 or 261 so it's hard to know if you're lowering them when you try diff things.

[JXE]

CStrickland, great idea about diluting the water to get a better idea of the true reading. I will absolutely give this a shot in the morning.

My water source is treated tap water. Once I get the readings in a good spot, I plan on adding two false perculas and that's it. Honestly, the water requirements for corals always scared me away in the past and as I come back to the hobby I'd like to stick to an area I'm comfortable with.

[CStrickland]

Totally understandable.

A small change you can make now that might help a lot is to stay up on maintaining your hob filter. They have the nickname "nitrate factories" because they catch crud and hold it in a high-turbulence area. That's diff from other places the crud would normally settle because you wind up with a diff bacteria population working on the crud. The bacteria that grow well on filters break the poop and stuff down into nitrates but they aren't good at the last step. When that same poop settles in a low-flow area an extra set of bacteria can grow that turns the nitrate into a gas that bubbles out of the tank.

So the fix is keeping your filters really clean. If you rinse them every other day or so, you will get the crud out before the factory turns it into nitrate. That will work together with water changes by adding less new nitrates while your getting the current ones out.

This isn't just for stocked tanks either. Even without fish the bacteria and worms and pods are popping and dying and cannibalizing 24/7. You can get even more bang for your buck by using a turkey baster or little powerhead to blow that crud out of the rocks an hour or so before you take the filter out to rinse it. All the crud you can kick up into the water and rinse down the drain is crud that won't add nitrates to your system.

Good luck and welcome back!

[CStrickland]

Oh ps honestly for a fowlr tank nitrates are not a freak out situation anyway. If you were trying to breed clowns or something maybe watch it more closely but fish toxicity numbers aren't even really established because they are so high. So make sure that when you google about this you aren't reading stuff meant for coral (which do best under 10ppm) and getting over-worried.

Of course you don't want an algae problem, and algae likes nitrates, but that's a cosmetic issue more than a "taking care of pets" one.

[JXE]

Update:

On the 15th I used a diluted tank water mix to determine how high the nitrates actually were. I determined it was about 200 ppm.

CStrickland's idea of using a powerhead on the rocks was a good one. I basically am doing a combination of everyone's thoughts. Yesterday I used a powerhead to blast everything inside of the tank as I siphoned water out of it. I pointed the powerhead directly at the substrate as well, which yielded a lot of extra gunk. I took out more water than last time, about 21.5 gallons... almost all of the water in the tank.

Today I ran tests and got the following results:

ammonia: 0 ppm
nitrite: 0 ppm
nitrate: 40 ppm

It seems like I'm getting there! After running the tank with nothing in it for so long and with minimal maintenance, I'm sure everything just built up and it needed a really good cleaning like I'm doing now.

I figure that I'll do this one more time and that should get it real low. My next step will be to add a skimmer again. My questions are as follows:

I assume that since I'm basically removing all of the water with these changes that I will witness a cycling period. Am I correct? Or will the crushed coral/live sand mix and live rock keep the levels pretty consistent? I wasn't planning on adding fish for a couple of weeks either way.

In the past I kept things like triggers in my 125 gal. tank, so I was never one to own a big cleaner crew because the fish would eat them. I'm thinking that since I'm only looking at 2 clowns in this tank, a cleaner crew would be a good idea. When is a good point to introduce them: before or after the fish? I'm reading that high nitrates were not as big of a deal because I was planning on FOWLR. If I add snails and hermit crabs, what is considered to be high nitrates with them in the tank?

Thanks for all of your help so far! The tank looks cleaner than it has in a long time and I feel like I'm making some progress.

[CStrickland]

That's great news!

Are you thinking about a CUC to eat algae? Sometimes that's less of a big deal in a fowlr tank because you don't have the bright coral lights growing algae. But if you want a CUC I think the hardier ones will be ok. I wouldn't try to keep an urchin or anything, but a couple hermits can be fun to watch and are fairly tolerant of parameters. I don't think it matters when you add them, but they might need to be fed if there's no fish yet.

The bacteria are mostly on surfaces so you don't have to worry about a cycle. Sometimes a project like this will foul the water a little by stirring up crud, keep an eye (or a nose I guess) out for rotten egg smell, that's a gas that can be trapped in old sand and is bad for animals. But since the tank has been empty you'll want to check ammonia before you add fish and keep an eye on it as you stock, in case the bacteria need to catch up to the new load. I doubt it will be an issue in a mature tank like yours though.

Congrats on the hard work and I hope your luck stays good !