Nitrate and general help.

[deano77]

I need some good advice. I have a 100 gal tank with 120 lbs of live rock and a 3 inch crushed coral base. My tank is 4 months old and due to some very bad advice and not finding this board untill too late I killed several fish. My nitrate levels are at 100ppm. I and changing about 1/3 of the water out every 2 weeks since the problem started the nitrate levels dip then go high. I am not running a sump or refugeum so I am looking at a hang on skimmer ( I only have 2 3/4 inches behing tank). How do I get the nitrate levels down? Will hi nitrate levels kill shrimp? I currently have a large sailfin tang and a fox face, a couple of green star polyps a bubble coral and a mushroom. a dozen snails and a dozen hermits everything looks healthy except the dead shrimp. I am thinking of buying a deltec 500 and putting in the "sump" behind the tank where the bio balls used to be. Any advice would be great. Thanks
Bob Dean

 

[danmhippo]

It sound like you've already pulled bioballs out. You mentioned sump behind the tank, is this a sea-clear tank?

One of the main source of nitrate is feeding. How much and how often do you feed your rish? Since you do not have a skimmer yet, I'd highly recommend you get one soon. If this is a seaclear tank, I would not know if any skimmer would fit your tank with the space limitation you've indicated, and yet would still be able to cope with a 100G tank. My best advice is you should consider if you can allocate a space in your cabinet for a sump, large enough to fit in a in-sump skimmer. The spaces behind the tank where you were planning for the small skimmer be converted for a refugium with some fast growing macro algae.

The primary mean of lowering nitrate would be the skimmer, as they will remove raw waste and ammonia based compounds out of the water before they have the chance to be converted to nitrite and nitrate. Coupled with reduced feeding and regular water change, nitrate level should fall to a manageable level below 50ppm.

 

[Len]

Hi Bob. Here I am

Nitrate isn't very toxic at all, but the problem that usually occurs with high NO3 is algae blooms. Your shrimp and fish won't die from nitrate toxicity. Unfortunately, for a 100g tank, there are no skimmers that can handle a tank that size. AquaC Remora and Deltech MCe 600 can come close, but they are still a bit underpowered. If the Deltec 500 can fit in that sump compartment, go for it! Otherwise, without a sump or refugium, it looks like you are relegated to water changes for some time to come. You can also try macroalgae in the short term to soak up some nitrates (harvesting it every month), but I would consider it a long term solution, especially if you get into stony corals.

Just a point to make: if the water you're replacing is high in NO3, it's not going to help dilute the problem. Make sure if you're mixing saltwater you're using high quality water such as that form a reverse osmosis filter. Otherwise, you're just adding back nutrients that you just removed.

Removing some of the crushed coral (and thoroughly siphoning any detritus in it as you go along) can help in the long term. It's a good time to do it now since your stocking levels are still low. YOu can consider either bare-bottom, a shallow layer of fine aragonite sand, or a deep sand bed (3-4" will suffice) in place of the crushed coral. CC simply has a bad habit of trapping a lot of detritus and allowing it to slowly leech back into the water w/o much denitrification occuring.

That's my two cents. Hope that helps. I'm sure others will have input on this matter

 

[deano77]

The 500 will fit. I think that I way overfed the fish. When I am cleaning the tank should i use a powerhead to stir up the waste matter on the live rock. Also I can't seem to keep shrimp alive, anything that i might check.
Thanks for the input.
Bob

 

[danmhippo]

What kind of shrimp? Do they feed in your tank? Did you see their remains or do they simply disappears?

 

[deano77]

They were cleaner shrimp (4 of them) they were working away on the fish for about a week then nothing. I have seen the remains of 2 of them and they did not look like they were eaten. Also on the Nitrate problem I am now using r/o water I tested the Tap water i was using and it was about 45ppm. Should r/o water mixed with salt read 0 nitrates. Mine is reading about 10ppm.
Bob Dean

 

[danmhippo]

Cleaner shrimps are pretty hardy. They die usually due to environmental factors such as water parameter pH swing, Alkalinity swing, temp swing...etc. I am not certain if nitrate is one of the causes.

10ppm is not that bad for RO water, with DI cargridge, the level would be even lower, but not necessarily 0ppm. Most salt mix now days should not contain nitrate or phosphate, so I suspect your water after RO reads about 10ppm.

What's your other tank parameters, especially pH, alkalinity, and temp in the morning before lights on and at night before lights off?

Cleaner shrimps BTW are omnivores. If they have other easier to get food, they won't be as active cleaning fishes.

 

[Mihai]

Where is Bob? Bob, you're sleeping on the job!
Now's your chance.

Seriously speaking, Len pretty much gave you good advice. One thing you may try *in addition* to what Len said is adding a HOB refugium with a fine DSB and fast growing algae that you harvest periodically.

Of course, a sump would afford you much more freedom in choosing a skimmer and a larger refugium.

M.

 

[deano77]

I am going to follow Len's advice and buy the deltec 500 skimmer, remove the crushed coral and possibly set up a refugium. Can you put macro algae in your main tank? If it's in the main tank do you need to keep it lit 24/7 to keep it from going sexual? How big a refugium do you need for a 100 gal tank? I had no idea how much I and my LFS didn't know!!

Mihai what is DSB.

My water temp varies bet 77 and 78. I need to chk alkalinity.

 

[Mihai]

Can you put macro algae in the main tank?

You can if you stand the look of them. Some of them (Caluerpa in particular) leach yellow stuff in the water, so you need to run carbon to get it out.

Regarding the size of the refugium... the bigger the better, just like the skimmer (although you can over-skim a tank you can not over-refuge it). Even a small one (say 5 gal) will make a difference although if you can get a bigger one will be better...

M.

 

[Mihai]

One more piece of advice: try to get a few tiny brittle stars from a local reefer. I got one (or two?) and now I have about 1000. The good part about them having in this quantity is that they find all food that is not eaten by lights out. In the morning there is nothing left to rot anywhere in the tank preventing it from decomposing...

M.

 

[Len]

Sure, you can put macro in the main tank. One of our members has been passionately advocating this very thing for a while now Macro will help to reduce nutrient levels; just make sure you keep them regularly pruned and their growth kept in check; skimming and carbon will help absorb the humic and tanic acids they release into the water.

It is important to control all aspects of nutrient processes. I agree with Danm's suggestion to keep feedings in moderation. No one thing will fix the problem, so your multi-prong attack is a good approach. It may take a little while, but I think you can successfully bring down your nitrate to below 50ppm. To be honest, if you aren't experiencing any algae blooms, NO3 is not really that great a concern.

 

[Len]

Oh, DSB = deep sand bed

 

[Anonymous]

I don't really have anything new to add to what Len said, but just to reiterate the main points:

1. This is actually normal for a tank of that age. It is also not terribly dangerous in itself to soft corals and clams, for the same reason algae enjoy it. (It can inhibit stony coral growth). The main concern is that it is an overall indicator of poor water quality, i.e., you may well be getting toxic build-up of stuff you are not measuring.

2. To lower it quickly, you will have to do a series of large water changes. If you produced no new nitrates, it would take five successive 50% water changes or 12 successive 25% water changes to lower it to 3 ppm.

3. The problem is worse if you are still producing them. Pretty much any mechanical filtration apart from skimming will create a nitrate problem due to trapped detritus.

4. A large-scale macro-algae farm, and/or a deep sand bed are probably the best way to curtail nitrates. Macro-algea sequester nitrates and thus remove them. The nitrogen cycle itself can only be completed when anerobic bacteria can reduce nitrates to nitrogen gas. This is a much slower process and takes much longer to become established. Those bacteria live in deep sand beds or in the inner core of live rock. It is a slow and inefficient process, and might take a year to become well-established. You can also get denitrification biological filters, but they strike me as difficult to employ. A refugium with a deep sand bed and a macroalgae farm is probably a better way to go and certainly more pleasant to look at. Another option is to use mangroves. I am thinking of trying that.

 

[deano77]

When I replace all this crushed coral with sand should I do the 1 inch bed or go for a 3 to 4 inch bed for future denitrification?

Do mangroves work as well as macro algae? Do they need constant light? Are ther hard to grow?
Thanks
Bob

 

[Anonymous]

I am going to follow Len's advice and buy the deltec 500 skimmer, remove the crushed coral and possibly set up a refugium. Can you put macro algae in your main tank? If it's in the main tank do you need to keep it lit 24/7 to keep it from going sexual? How big a refugium do you need for a 100 gal tank? I had no idea how much I and my LFS didn't know!!

.

You can put macros in your main tank if you want to, they can get out of hand and become more of a maintenence chore than you may want to deal with. I prefer no macros in tank, because I can't stand spending time picking them out from around corals that are bothered by the close growth. Caulerpa got all into the base of my birdsnest coral once.

BUT! I see you have a sailfin tang and a foxface. With those two, I think they will eat it all before it gets established. Is there anyway you can partition off part of the sump you have with a piece of acrylic, and put a cheap light over it?

 

[Len]

Magrooves work well, but they are a lot more difficult to grow. Macro is plug and play organisms

Here you go:
http://www.advancedaquarist.com/issues/ ... eature.htm
All the mangroove information you need to get started if you so choose that route.

 

[PamRich]

Whith regard to the suggestion : <to get a few tiny brittle stars from a local reefer.> Don't get green brittle stars as they get huge and will eat your fish, red serpent stars are better. -- I think what Mihai might have been suggesting were tiny sand stars... not brittle stars

 

[Mihai]

Whith regard to the suggestion : <to get a few tiny brittle stars from a local reefer.> Don't get green brittle stars as they get huge and will eat your fish, red serpent stars are better. -- I think what Mihai might have been suggesting were tiny sand stars... not brittle stars

First point: most brittle stars do not eat fish - only the green brittle star does.

Second, I really meant the tiny ones, my largest is 1.5" diameter and they don't grow more than that. They are all white and are all over the Hitchhicker forum. They are true brittelstars, just don't grow as big as the other ones (and they multiply like rabbits - even better).

M.

 

[PamRich]

< tiny ones, my largest is 1.5" diameter and they don't grow more than that. They are all white and are all over the Hitchhicker forum. They are true brittelstars, > Yep Mihai, those are the sand stars I meant, never knew them to be "true brittlestars" learn somthing new every day I guess..... a beginner will have to be careful not to go buying any green brittle stars