Fuge(s) + Nitrate Inquiries

[fiveldsp]

I have a 125g tank which was set up 7 years ago with a complete drain and move about 2 years ago. I have always had higher then desired nitrates and I want to finally put it all out there to get feedback from the experts to make sure that what I think I know is what it really correct.

Some of these numbers are going to be more of an estimate just because I started the system so long ago I don't have exact numbers any more.

Main Tank Equipment:
4 Maxi-Jet 160gph powerheads w/ quick filters (cleaned weekly)
2 AquaC Remora Pro Protein Skimmers with 800 pumps (211gph each)

Main Tank Lighting:
3 250W MH 10K (4pm - 9pm light cycle)
4 T5 15K (12pm - 12am cycle)
5 blue LED moonlights

My sand bed is about 3" deep now in most spots, guessing about 130 lbs worth. I would guess that I have over 200lbs of live rock. Both the rock and sand have been in the tank since day one.

In the center at the back of the tank I have an overflow that siphons over the top and drains down into my first fuge, a 10 gallon tank. The water drains into the tank through a pvc pipe with holes in it into the tank. This tank has a 2" sand bed of live sand with chaeto growing on the right side under the drain - and on the left side I have some xenia and mushroom frags that I plucked out of my display tank. There is egg crate in the middle of the tank to prevent the chaeto from clogging the siphon.

Now from that 10g tank, I have another siphon that connects that tank to a 20g bare bottom tank with live rock rubble and coral rubble. There's also some shells in there. Whenever I do a water change, I use the siphon hose to suck up detritis that settles on the bottom of the 20g under the rubble. There's a 24" fluorescent bulb that hangs above both of these tanks. From the left side of the 20g, it pumps back up into the display tank.

I used to have an actual acrylic refugium with baffles and the like and I had 2 of them fall apart and drain my tanks onto my floor... so that's why I prefer using actual fish tanks - although am not opposed to gluing in baffles if it would really benefit the system.

I also wish that I could have one single large tank underneath but since the tank is already established... I am limited to what sized tanks I can squeeze under there without disassembling the stand and I really don't want to jeopardize the stability of the stand.

Over the last 3 days I have done 3 water changes... one each day. I don't have the liberty of doing 50% water changes because of the amount of rock that would be exposed to air and I don't want to go through a die off just for a water change. First day I did a 20g change, second day was a 35g change, third day was 20g change. I am using Instant Ocean salt mix. The reason why I want to double check on all of this is because I have been testing my water before a wc and several hours after the wc and my nitrate levels aren't changing in the least. I am sitting at 50 ppm. I have gotten similar test results using both a Red Sea test kit as well as Salifert test. Below are the other levels in the tank.

Temp: 80-82
Ammonia: Undetectable
Nitrite: Undetectable
Calcium: 450
pH: 8.2
Alkalinity:1.9
SG: 1.025

I use an RO/DI system from THEFILTERGUYS for my mixing water and have tested it to show 0 nitrates in mixing container after adding the salt.

Livestock in my tank is low for its size.

1 ocel clown paired with 1 black ocel clown in host sebae anemone
1 bangai cardinal
1 Kole Yellow Eye Tang
1 Flame Angel
1 Royal Gramma

Assorted leathers, mushrooms and polyps corals
1 Crocea Clam
1 Gold Maxima Clam
4 serpent starfish
1 sandsifting starfish
4 hawaiian feather dusters
hermits, snails and a pencil urchin

I also have 2 separate frags of Halimeda (money plant) growing. I plan on continuing the water changes to keep the levels at their current readings at least with the hope that the nitrates will come down. I have not had any losses in my tank for a long time and I clean my equipment biweekly, alternating powerheads and siphons one weekend and skimmers the following weekend, then repeat. Any information at all is always welcome and appreciated.

 

[BigAl07]

Here's what I see right off the bat . . .

A) Live Rock Rubble, Coral Rubble, Remnant Shells are all collectors of detritus and "junk" in general. In my eyes it's a recipe for NO3 from the day it's added to the tank. Unless you take it ALL out fully and clean it fully (which sort of defeats the purpose no?) it's going to collect detritus.

B) You water change amount isn't enough. NO3 reduction is directly proportional to water change percentage. 30% water change would net an approximate NO3 reduction of 30%.

20g = 16% 50 * 16% = -8 or net of 42 (almost undetectable with HOBBY grade testing)
35g = 28% 50 * 28% = -14 or net of 36
20g = 16% 50 * 16% = -8 or net of 42 (almost undetectable with HOBBY grade testing)

It's ok to allow your rock-work to be exposed to air (without the lights COOKING them though) for a little while. Just don't expose any delicate coral that would be damaged (Hammer, FrogSpawn, Anemone, etc)

I'd like to see a couple heavy water changes in conjunction with making some subtle changes underneath to help nip some of the problem at the root.

I like to see the NO3 down in at least <20 and then let the tank go for a week and test to see just how quickly they come back up. Then decide what to address next. The trick is to do nothing DRASTIC.... slow steady changes.

 

[fiveldsp]

Wouldn't any sponge growth on the rocks that would be exposed die off from exposure to air?

Other than sponge growth, I could drain half of the water from the display tank with only exposing leather corals and a zoo colony. What kind of leeway do I have on time with this? I use a 1/2" siphon tube and to drain that amount of water would probably take a good 10+ minutes plus time to fill back up.

I guess I always get a little nervous when it comes to doing things outside of my usual routine, so exposing half of my tank for even 10 minutes kind of scares the crap out of me, lol.

In regards to the refugiums... I like the idea of keeping the tanks down there for pod growth as well as extra water volume... but should I just remove all of the rubble and use both tanks with sandbeds and algae? All of my equipment sits on the back of the tank, so I don't need to use any of those tanks as sumps.

I remember reading an article probably 5 years ago about using live rock rubble as a natural filter and it never occurred to me that the logic or knowledge behind it or the pros and cons would alter over the years. It was easy to siphon out debris on the bottom but you're right... without washing off each rock it really wouldn't matter. Thanks for the insight and anxious to hear more...

 

[DaveK]

In addition to the excellent points made by BigAl, which I generally agree with, There are a few additional things I would do.

Consider investing in a larger skimmer. As much as I like AquaC Remora Pro skimmers, even using two of them, it is asking a lot of them on a 125 gal tank.

Consider a new circulation system over the Maxi Jets. If money is no object something like the Tunze stream pumps and a controller, or Ecotech Marine Vortech pumps will give fantastic flow. However, if your "dirt poor" like most of us, Hydor Koralia's will work well also.

Also check your feeding schedule. You could be overfeeding, and not know it.

 

[fiveldsp]

I actually have a Hydor Koralia sitting on my kitchen counter partially dissected trying to fix it. I had the thing for 2 weeks and it tied up it would seem. That's happened to me twice now on that brand and so it's failed to impress me so far. I wouldn't say that I am in the range of dirt poor although there is still a limit to my "play budget". However, despite frequent cleaning every other week, those powerheads are the original ones I purchased for my tank 7 years ago... so even if they were perfectly clean... general wear and tear over the years would have decreased their flow.

In regards to my skimmers... I actually misquoted the pump I had on them... I have the RIO1400 on one and the Mag-Drive 3 on the other. Was hard to tell with all of the algae and calcification on them but managed to find the boxes today so thought I would update it. Both are ranked for 120 gph flow which I felt gave me descent skimming for roughly double the volume of water. What should the gph flow in regards to skimming be for a water volume similar to my setup? I've always been curious about the stand-up models that sit inside a sump because of their ease to clean and perform maintenance on... I actually broke one of my Remora Pros just a month ago when i tried to lift it off the back of the tank to clean and it slipped and smashed into a dozen pieces behind my stand.

If I were to upgrade to a sump based skimmer... what skimmer and pumps are recommended that perform well for a reasonable cost?

In regards to feeding... I only feed frozen food now, mainly clam, brine shrimp and mussel. Every few days I mix in flakes with garlic. I use 1 cube of frozen food and feed with an eye dropper slowly to the eager kids. I turn off all of my powerheads during feeding and generally only feed them half of a cube at a time. I feed them the 2nd half of the cube later that day. I don't target feed any of my corals or invertebrates with cyclopedes or any other coral food.

 

[fiveldsp]

Well the process has begun so we'll see how this goes...

I shut down the circulation between my display tank and fuges today and started picking out the live rock rubble from the left tank of my system. Had to go slow because I knew there were bristleworms in there so it took awhile to pick them out. Any piece with an interesting hitchhiker went into the other fuge to spy on later. After all of the rubble was out, I siphoned out the rest of the water and detritis from the bottom of the tank using a turkey baster to get the very last bit. I wiped down the tank with RO water and filled it back up with prepared water that was originally going to be for a water change anyways.

I removed the entire plastic tube between my fuge pump to the valve at the top of the tank because there were connections in there that weren't necessary and I wanted it more streamline. Upsides to this is I removed any gunk that could have been growing in the old line and MAN did it increase the flow from that pump. My overflow drain into the fuges is actually having trouble keeping up and it has a 1" diameter line coming down. It also has several joints and angles to it that I don't like and was originally built for the first acrylic fuge I had, so tomorrow I'll head back to Lowes to buy pipe to replumb the line down to also start with a clean line as well as remove unnecessary bends and joints.

So tomorrow's agenda is to finish plumbing and do the cleaning on the powerheads in the display tank. Saturday I am going for my first big 50% water change. It's going to be a guess on what 50% of my system volume actually is... but I'm aiming for 65 gallons, which with rock and sand plus 2 fuges should be close to 50% i hope.

Again, thank you guys for the support and advice and the continued assistance on a cleaner and safer home for my friends

 

[GrendelPrime]

any updates?