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Safe Zone for Nitrates in a Reef Tank

26K views 37 replies 6 participants last post by  gus1911 
#1 ·
I just read an article that stated (by an apparent experienced, or perhaps even a professional) reef keeper that 0 - 20 ppm for nitrates is Ok for a reef tank.

When I converted my all fish tank to a reef tank months ago my nitrates were high - really high. I had fish and soft corals in the tank and they did fine - no deaths and apparently no stresses on anyone. I'm not so much worried about stress or death among my soft corals or fish - they seem to handle 10 ppm of nitrates easily. The soft corals are growing like weeds and spreading. Softies is all I intend to keep - no stony stuff.

My big concern is hair algae. It was the death of my first reef tank 20 years ago and I gave up in disgust and dissapointment. Now I'm trying again and all is well so far. I can keep my nitrates below 10 ppm with a 10% water change once a week. That's easy to do, it works fine, and I'm committed to doing it. Every week.

The big question is: Will 10 ppm keep the dreaded hair algae away? If I see any hair algae again, I'm running off to Tahiti to live out my life in peace.
 
#2 ·
I can keep my nitrates below 10 ppm with a 10% water change once a week. That's easy to do, it works fine, and I'm committed to doing it.
I would challenge this statement, based on pure mathematics. With any proposed daily increase in Nitrates, keeping a system at 10ppm with 10% weekly water changes does not mathematically work. I have a bachelors in actuarial science. We can do the math, or you can just trust me on this and lets move on. ;-)

On the flip side, you may be achieving this result due to natural denitrification within your tank. Rather than rely on water changes, perhaps you could identify more natural methods of nitrate reduction & prevention, to assist this denitrification process.

For example, do you use mechanical filtration? If so, removing all filter pads will help to eliminate unnatural sources of nitrate buildup, allowing the nitrates to naturally fall as denitrification occurs.

I am willing to bet that with a little examination of your tank we can get your nitrates to zero naturally, without all the effort. If you are interested, post some details and pictures of your setup.
 
#3 ·
In a reef, you can achieve 0ppm nitrates, which is what you want.

My reef, last time I checked, was very close to that. I'm going to be honest: I don't do waterchanges every week. I do them every 2 weeks to a month. My water quality is great, and if something goes wrong, I potentially know about it because of my Pulsing Xenia. To me, they are a water quality-watcher. They have never stopped pulsing. If the aren't, something is wrong.

The best way to achieve nitrates under 10ppm, or even 5pp, (IMO), is a quality skimmer, live rock, and plenty of water movement. Along with WC"s, of course.
 
#4 ·
Ok - let's move on. Sounds interesting.

Tank is 20 gals, ph 8.4, phosphates 0 ppm, lighting is 96 watts of T5 HO 8 hours a day. As of today nitrates were about 10 ppm. The last water change was 6 days ago, and I plan another 10 - 15% change tomorrow. I have no skimmer. The noise from the Venturi won't work in my setup because I have the tank in our family room where we watch TV and listen to stereo. Unless I can find a quiet skimmer. I'm depending on whatever water changes I need to do to keep the water quality as good as it is now.

I have 15 lbs of live rock over a bed a dead rock. I can't stuff any more live rock in the tank - if I do there won't be any room for corals.

I have mechanical filtration - an HOB filter with carbon, filter pads and a nylon bag containing Purigen to help with the nitrates. The tank is 2 1/2 months old and is doing fine. It's a conversion from a fish only tank, so there was no break-in period or new tank syndrome. I simply began adding the live rock a few lbs at a time every few days, then a soft coral once a week. The fish were already there, a clown, a wrasse and a damsel.

The tank is doing fine, and naturally I want to keep it that way. Water changes are not that big a deal for me since the tank is only 20 gals. I've kept small saltwater FO tanks for 20 years with sucess so I know what I'm doing (I think?) with small salt tanks.

This pic of my tank was taken this afternoon, when the anemone in the lower right was spread out like a corn fed pig, the Xenia in the upper left was in full bloom and the mushrooms were in full spread.

Thanks for any advice. It sure would be nice to see 0.0 ppm of nitrates for the first time in my life!!

http://silkentent.com/gus1911/Storage/Aquarium July 30.jpg
 
#5 ·
Your aquarium is beautiful. Very nice display.

Obviously, without a protein skimmer you have a unique challenge. But knowing the downfalls of such a system allows us to take correct actions.

You are using activated carbon, which on a 20 gallon tank has the ability to nearly replace the benefits of a skimmer. It is very important that you use a high quality carbon and replace it frequently. I would personally consider a weekly replacement of the carbon, to allow it to absorb organic acids at maximum efficiency. This will help to reduce the amount of organic waste that is available to be processed biologically.

Another step will be the frequency of cleanings of your filter pad. On a system without a skimmer, I would make it a routine to give the pads a rinsing every morning and every night. Organic waste bonds with these pads, and as water flows across these organics, they break down causing an increase in nitrate and phosphate levels. By rinsing the pads 2 times per day, you will be directly removing waste before biological activity occurs.

The purigen bag is another possible source of biological activity. Have you tested the water to confirm that the Purigen is effective at reducing Nitrates? If you are not seeing a visible benefit or test results confirm this, I would remove the bag. This pouch is a source for bacteria to cling and begin biologically breaking down organic acids, depleting carbonates and producing nitrates. In a larger aquarium the benefits could outweigh the negatives, but on a 20 gallon tank without a skimmer, any artificial biological processing of waste is bad.

Fortunately for you, you have a considerable amount of live rock. This rock alone is very capable of handling all the waste load produced in your system, provided you make these small steps to help out. Keep in mind, live rock processes organic waste with an end result of nitrogen gas, which leaves the system naturally without ill effects.

Finally, ensure that you have adequate water flow across the substrate. Your larger grain size will make it easy for detritus to settle, which should be avoided. A good clean up crew will be essential.

Hopefully you have a few take aways from this. Congratulations on your success.
 
#6 ·
Pasfur - your comment about the Purigen was enlightening to say the least. I read everything I could find for days on nitrate elimination methods and settled on Purigen. No reactor is necessary and the manner in which it works was claimed by those who use it as the best nitrate reducer on the market (it duzzint really remove nitrates, it removes only the "stuff" that creates nitrates). The Purigen has been in the filter for only 10 days but I have noticed no benefit in nitrate reduction. Hmmmm. Your question "did it help?" is thought provoking, but I have to honestly answer "NO."

Okay. By day's end the filter will have only pads and activated carbon. No Purigen. After my weekly water change

Now comes a big confession of an item that I completely forgot to mention in my previous post. And it's important. After you read this, please don't send the Saltwater Reef Police after me!

In the 20 gal tank I had an undergravel filter. Never had a problem with UG's. When I strted with saltwater FO tanks, UG was the way to go. When I decided to convert to FOWLR I left the UG in place. Then, because everything was going so well, I decided to add more live rock and try some soft corals. Still, everything was great - weekly water changes kept me in business.

I know that UG filters or a "no no" in reef ranks. But it's too late now. I won't tear the tank down and start over, and I can't turn the UG off for obvious reasons.

SO - do you wanna take a crack at an option for me? Remember, it's not causing me any grief now. Should I leavet it alone, phase it out slowly (I have no idea how to do that), or WHAT? Does anyone besides me use a UG filter for a reef sucessfully? Am I a pioneer in this UG area or just someone headed for trubbell?

One last item. I have no intention of keeping any hard corals, it's softies only for me. My concern is hair algae, the scourge of every reefer.
 
#7 ·
In the 20 gal tank I had an undergravel filter.

I know that UG filters or a "no no" in reef ranks. But it's too late now. I won't tear the tank down and start over, and I can't turn the UG off for obvious reasons.

Does anyone besides me use a UG filter for a reef sucessfully? Am I a pioneer in this UG area or just someone headed for trubbell?
I'm not kidding when I tell you this... it is true... it is 7:35am in the morning here in Louisville, KY. I just laughed so hard my wife woke up. Try explaining to your wife how funny it is that somebody uses an u/g filter in a reef tank. Yeah...

Ok, the answer is obvious. Don't fix what isn't broken. You have a beautiful aquarium, so why go tinkering with the substrate? I would leave it alone.

However, if someone else were in your shoes, and they were experiencing the sort of problems you'd expect with an u/g filter system. i.e high phosphates, uncontrollable nitrates, alkalinity depletion, calcium depletion, and pH swings.... then I would advise this person to turn off the u/g TODAY. Just leave it in place, but stop the water flow. Then add enough live sand (well rinsed in aquarium water) on top of the existing sand to reach a total depth of 6''. A bacterial bloom may occur, followed by some cloudiness, but in the long run the tank would be better off. This is a plenum system, not to be confused with a DSB.

For the record, if you think back 15 or 20 years, when the concept of denitrification was first achieved, the idea was to convert a u/g system into a plenum system by turning off the water flow and increasing the sand depth. ;-) Today, we have now discovered that DSB systems are more effective without a plenum, and are achieved most effectively by placing the proper sand directly on the bottom of the aquarium, using 4''-6'' of sand, and lots of sifters.

LOL An u/g filter.
 
#8 ·
HEY!!! I just had to tell my wife that two people in Lex Ky are laughing at me because I'm using a UG system in my reef tank!

Remember, this was not planned. When the live rock worked so well, and I added a few corals and that seemed to be working, I kept right on going. All unplanned. Now a tear down seems like an awful idea.

This I know for fact. My nitrates are not increasing, they have been at 10 ppm for about a month now. I can only conclude that my waterchanges, live rock and Purigen are working together to kep the nitrates at a manageable level. I might try several big water changes in successive days to get the nitrates as low as I can, then see if they increase. If they don't increase, then that's a good enough reason to leave well enough alone.

I'm not averse to trying your suggestion of turning it into a backward compatible/half baked plenum system if my pioneering effort here fails me. However, if in five years my UG system has revolutionized the reef tank hobby, and the system is named after me, I will remind you that you were the one who laughed at me first!!!

Thanks for your help. You have been a big help, I have a few choices and I will keep you posted - with news both good and bad. Pictures too - both good and bad.
 
#12 ·
I'm familiar with the reverse flow UG filter method. Some salt folks must still use it because Hagen still makes reverse flow power heads. Are you suggesting that I try this now?

I think I would rather wait to see if my Gus1911 UG Reef Filtration System (pat pending) fails me. So far this tank has the best water quality of any tank I've ever had. And my softie corals are exploding!

I see where I can shift some stuff around and make room for several more pieces of live rock. I know more live rock will help. If I need to sacrifice some corals for more live rock, I would do it.
 
#13 ·
im not saying you need to do anything as ultimately anything you do with your tank will be your choice, but IF it was my tank/choice thats what i would do. the undergravel filter, how its working now is pulling food/poop down, eventually there will be build up which eventually breaks down into nitrates and phosphates which algaes feed off of. you may be seeing the worst of it, at only 10ppm nitrates. believe it or not, softies also like alittle bit of nitrates in their water so this is prob. why they are loving it.

and just for the record, my reef has constant 0 ppm nitrates even after heavy feeding. i have alittle over 100 gallons total system water and run an over rated skimmer.
 
#14 ·
In my opinion, the only reason this is working for you is that your aquarium has a ton of live rock. The rock is effectively serving as denitrification to keep nitrates at some controllable levels, despite the constant pumping of nitrates into your system by the u/g.

This is fabulous.

By the way, I am from Louisville. You know, as in the Louisville Cardinals basketball team coached by Rick Pitino. We don't think it is very funny confusing us with those hicks that live down in Lexington.
 
#15 ·
By the way, I am from Louisville. You know, as in the Louisville Cardinals basketball team coached by Rick Pitino. We don't think it is very funny confusing us with those hicks that live down in Lexington.
Sorry. I'm a graduate of Maryland, and a big fan of Gary Williams and college basketball. To mix up Louisville and the Lexington hicks is unforgivable!!:oops:

Back to the live rock. You said I have a ton of live rock. I thought the right amt was 1.5 lbs per gal of water. I should have much more than the 15 lbs I have. Did I miss on that one too??:oops::oops:

onefish2fish - Reversing the flow of my UG will be my plan B. As long as everything remains as is, I'm just going to watch and wait.
 
#16 ·
Forget the old pounds per gallon of live rock rule. Look at your tank. It is packed with rock. If you only have 15 pounds of rock, then the rock you have is extremely porous and low density. It is the quantity of rock that is important, not the mass of the rock that results in its weight.

Back to the u/g subject. I think the worse thing you could do is reverse flow. Right now you have very little accumulation of detritus under the u/g plate, because the power heads are moving water at a rapid pace. If you reverse the flow, you will have waste trapping itself against the bottom of the u/g plate, unable to move upwards threw the gravel bed. Detritus will accumulate and phosphates will become a problem.
 
#18 ·
Would you please elaborate on what you mean by "keeps everything in the water." And what the advantage is for doing this.

Before and during this "reef tank adventure" of mine I've read literally thousands of words on the subject,for both large and small reefs. As with any venture or hobby, reefs especially, one encounters all sorts of setups, some loaded with contraptions that work and others with the same gadgetry that claim it's all worthless. Same with additives. I'm sure there are as many ideas and methods for keeping a reef as there are reef enthusiasts.

I've read countless posts on these forums and other articles where folks have reefs with plenty of live rock, protein skimmers, RO/DI units, UV sterilizers, sumps, refugiums and perhaps even a CD player thrown in for good measure, and they're puzzled because their nitrates are 40 - 60 ppm, and their tank is being overun with cyanob and hair algae. The book says "no way" but they are proof that it can be so. I have personally seen, close up, tanks that have nothing but live rock and a protein skimmer - nothing else, that are the best I've ever seen.

I suppose each of us needs to confront and solve our own demons, sorting out the best advice from the folks who know best, our personal experience, personal past history and the uniqueness of one's own tank.

As long as I can maintain my water at the quality it is now, undetectable phosphates, 10 or less ppm of nitrates, the sensible approach would be to not touch anything. At least until I see disaster looming.

I appreciate the advice I've gotten from both of you and I'll consider everything. But for now, nothing changes. Many thanks. I'm cool.8)
 
#20 ·
gus,

my tank has a constant 0 ppm nitrates. the keeping detritus in suspension is simple, corals feed on it. the method your using is pulling it down, trapping it over time. im not saying you can or cant run a tank this way or that way and people have had sucess with some wild systems and methods but im rather suggesting another way of doing it which IMO is better, but ultimately it will be your tank and your choices.
at the very least post some pictures up :wink:
 
#21 ·
I was determined to make this reef a sucess without tearing it down and starting over. I decided that my UG would stay, and I would keep after the nutrients with water changes. When I realized that I couldn't do that satisfactorily (I was doing three 15% WC a week) I bit the bullet and began my research on buying a skimmer. A quiet one was a must, and it had to fit in my 20 gal, and it had to have good reviews and recommendations. I reviewed, and compared, and read, and measuured, and made phone calls to mfgs until my eyes began to water.

On Tuesday of this past week, I installed my venturi designed Seaclone 100, and it's working even better than I had hoped. AND - it's quiet - really quiet. I also placed a small bag of Seachem de-nitrate in a small, low flow HOB filter. Again - a big surprise. Just as soon as I get a good picture uploaded to my web site I'll post it, with my results of the past week, and my latest water parameters.

Later.
 
#23 ·
I don't know either. I think the bad press came from owners of the old model before the improvements. The bubbles entering the aquarium was (is?) a sticking point, but with mine it's not a problem. Just a few once in a while. Aquarium Systems tells me that after the break-in period the bubbles will stop completely.

More nooz to come.
 
#24 ·
Here's a pic of my reef taken yesterday (Friday). I haven't done a WC since Tuesday morning and my nitrates are still <10 ppm (about 5 ppm) and my phosphates remain at zero. I will do a WC tomorrow (Sunday) because I intend to do a WC once a week minimum, two if my measurements begin to creep.

I'm not about to admit that my reef is now stable. It should be interesting to see how my parameters go in the next week or two. I'm sure I'll have more questions, so you folks that have been providing me with helpful info will need to be at the ready. I appreciate all of it.



This pic was taken a few days ago, before I switched some shrooms around.
 
#25 ·
The pic above of my reef tank is not the one taken Aug 15. I updated with the most recent changes and additions to the livestock. This pic was taken 2 days ago (Aug 22).

It appears that I will be able to keep my water parameters where I want them to be with 15% water changes every 4 or 5 days. For me that's 3 gallons for each change. Hardly a demanding chore, and not likely one that would allow me to fall into "lazy mode."
 
#26 ·
Starfish With Only Four Arms??

This hitch hiker appeared on my glass yesterday. In looking for info on starfish I found that starfish have 5 arms. Is this not a starfish? Any idea what it is? It's about 3/8" in diameter, and I'm sure it will grow.

 
#27 · (Edited)
The Starfish looks like an Asterina Star, they split loose legs.

What test kits are you using to test your water?

"I have always had good experiences with the SeaClone Skimmers "

What skimmers have you compared it to?
There is a chance you think its doing good, A good skimmer can full a collection cup with crap that looks like you did an oil change on your car.

There is a difference in skimmers Good ones like ETSS, BK, MSX, ER will pull a lot more skimmate out of your tank then a SeaClone.

I don't know if you are using a UG filter, that not good for a reef tank. & that rock on the bottom is not helping in lowering nitrates & others. SSB with cleanup crew or bare-bottom, RO/DI water & heavy skimming should improve water quality.
Just my 2¢
 
#37 ·
"I have always had good experiences with the SeaClone Skimmers "
What skimmers have you compared it to?
There is a chance you think its doing good, A good skimmer can full a collection cup with crap that looks like you did an oil change on your car.
There is a difference in skimmers Good ones like ETSS, BK, MSX, ER will pull a lot more skimmate out of your tank then a SeaClone.
I just noticed this comment, some 4 months later. I was the person who said i've always had good experience with SeaClone Skimmers. The other skimmers listed above are better, no question, but this is a 20 gallon soft coral display that would be very adequately skimmed with a Sea Clone. I will leave it at that.

By the way gus, beautiful display. As we discussed before, I don't think the u/g filter is causing any negative effects on your system due to the particle size of your substrate and extensive amount of live rock. However, I don't think it is providing any benefits either, other than water flow.

I appreciate your comments on Poly Filter. I have intended to give it a try in the sump of my 180 FOWLR.

In any case, awesome job.
 
#28 ·
The quote about skimmers was not my quote. I didn't compare my Sea Clone to anything. But, there were some conditions that had to apply to the skimmer, the most important being that it had to fit in my tank, meaning it had to be HOB. I only have a 20 gal tank, and no room at all for a sump and more pumps.

Everything that you've commented on has been commented on before. Everyone is upset about my UG filter. SO AM I. I know it's not a good filter for a reef - BUT - I had no intention of setting up a reef when I set the tank up 6 years ago. I did not want to tear down the tank and start over.

I slowly decided to convert it to a tank with just a few easy soft corals, and when they did well I added more, and I am now where you see it above. The tank is doing fine. This might be an experiment in how to do things backwards and still get good results. Or, it might crash Big Time some day soon. Nonetheless, as long as I can keep after the tank with simple 2 gallon water changes at a time, I'm not going to change anything. If things go south on me then I'll need to make some decisions.:evil:

I appreciate your input - even though you valued it at only 2 cents.:lol:
 
#29 ·
I don't think people are upset at your UG filter, Im not! I think people are trying to help, at least i was.
Honestly i was interested in your test kits.

Im new here, but not new to reef-keeping. Just trying to help. I hope i pulled the right starfish name out of my hat.

Good Luck!

Just my
 
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