Nitrate Reduction - the real facts

[May&Bruce]

I imagine this topic has been discussed many times before, but with the risk of being flamed by long-standing members, I wish to discuss it again.

Most books and so-called 'experts' say that we should aim to achieve 0 nitrates in our tanks. But really, is that achievable, and is it necessary? Do we worry too much about reducing our nitrates? Do we spend too much money trying to achieve 0 nitrates and then get all worrind and frustrated when we can't? Personally, i think so.

I used to wory asbout it all the time. I had a 3 foot reef tank that I could never get nitrates below 50. My 5 foot tank has a plenum filter and a good large skimmer; is not overstocked nor over fed. Nitrates are at a constant 10-15, and I am happy with that. It has only been running for 4 months so the plenum/DSB has not kicked in yet in regard to reducing Nitrates further - by all accounts, it will take many more months.

The importance depends to some extent on what sort of tank. Several references have stated that in a fish only tank, fish can easily put up with Nitrates over 50. But, corals/inverterbrates are supposedly far less tolerant to high levels of Nitrates. However, well know coral/reef guru Julian Sprung states in one of his books that many corals actually do well in the more Nitrate-rich waters (up to 40 or so, I can not remember the exact figure he stated).

Clearly, the lower the nitrate the better, but striving to achieve zero levels may be a waste of time, and actually quite unecessary.

A lot of reefers out there say that theiur tanks have 0 nitrate levels. But is this true? Come on guys, be honest.............

Finally, it seems to be very hard to find an accurate nitrate test kit. I now have three test kits and the all give different readings. During cycling of my 5 foot tank, I had a water sample tested by a repoutable analytical laboratory in Singapore. The Nitrate level was 4.5. Two of my test kits showed the level to be over 20 and the third test kit said it was between 5 & 10. So, some of you may think that your Nitrates are high when actually, they are not!

At the end of the day, the real test is how healty your tank looks - if your fishes and corals remain healthy month after month, then surely you don't have a Nitrate problem

....let the flaming begin............

[andylee]

The flaming starts from me

I agree with your point..

Nitrate always over 50 but then why LS still alive n kicking??

[May&Bruce]

Exactly....we shouldn't loose sight of the fact that high nitrate levels are definitely not good, but levels around 50 or so might actually be not too bad.

[andylee]

Been trying hard to reduce nitrate couple of months back

Did 30% water change at first every week.. then gradually increase to every 4 days.. problems still exist..

So decided to just give up trying to bring down nitrate but LS still healthy.. so think shldn't be a problem

[hammy]

well ...no matter what i do , the nitrate seem to be hovering around 20-30ppm.

decided to stop playing the number game and as long as my tank look okie . i am fine .

but with that i will at least do a 20% water change every week

[May&Bruce]

yep.....i did the same thing on my 3 foot tank. Ended up doing 50% water changes every couple of weeks, but Nitrates, would just not come down.

I am doing 10% water change on my 5 foot tank every two weeks. Hopefully I will never need to increase that (10% change on a 650 litre tank is a pain in the ######!).

[jonathan543]

for me, the last time i tested my water using salifert nitrate test was almost to 100ppm.... tried every thing from changing water to adding sugar(tank crashed halfway) then aiya! dump the test kit somewhere elses liao. as long as i change 15% of the water weekly & the ls all looks fine, i freak care liao... haha. and all my ls are healthy & looks fine to me when the nitrate's 100ppm...

[gods_angel77]

At initial stage I use to do monthly 10% water change for my 4x2.5x2 tank but recently just change the schedule to 10% water change every 2 months. (Starting to get lazy Lah)

I discover my NO3 is always between 2-5ppm use a deep sand bed system 18 months system

Other water perimeters are listed below

Ph8.2

No2:0

No3:2-5ppm

Nh4:0

Kh:9

Ca:410

Mg:1260

Sr:16

Specific Gravity:1.024

Salinity 30 ppt

Anyway I feel is good to do a monthly water perimeter check so that you can actually communicate with your tank

Lastly if all your coral & fish are healthy just don't care nor worry so much loh

[Dazza]

my nitrate range 5-25 ppm... happy with that n has been in this range for looonnn ggg time already ... i geuss impt parameters to note wud be more the ammonia n nitrites as these can be fatal even in minute amts... nitrates less of a wori imo

[blueheaven]

I am proud to say that my nitrate level is undetectable (notice I use undetectable)

The reason why we want nitrates to be as low as possible is not of it's mild toxicity but that it is needed for the growth of nuisance algae

And the main reason why we reefers are so worried about nitrates is that it is totally soluble and cannot be precipitated or abosorbed by any filters.

[vito]

As I know that nitrate at 20mg/l is still fine for most LPS coral except SPS they need to be below 20mg/l I wonder Do you guys use sysnt Salt water ..? if like that should be can control the nitrate level below 20mg/l unless you use natural sea water ...So this nitrate high level not cause by Bio ball right ..? or sand bed ..?

[blueheaven]

Actually, I didn't notice any browning in my SPS when I got my nitrate spike after I removed my sandbed

The biggest contributor of nitrate is probably sea water from LFS and tap water

[somebody]

hey, those bros that say that your tank has been 20(or whatever firgure)ppm for a looong time, do you guys still change water regularly? or what? how come can stay constant one? i thought it'll definitely go up with time and feeding?

[KTLK]

IMO the issue of claiming 0 NO3 must be accompany by also stating the water change involved. If I change water very often then 0ppm or low NO3 level is not surprising. IMO a gd system will have low NO3 even without water change for say 3-6mths.

[somebody]

fwah! how to do that!! =)

[newmarine]

Hi, I also have the same problem with nitrate. Tank had been running for about 1.5 month. The reading had been flutuating between 80-100 the best reading is 40 when I put in the coralife anti nitrate but 3 days later went back to 80. However, all my coral seems ok. Did water change but don't seems to be able to bring it down. Not sure what cause it.

[Tigger]

My tank has 100ppm of NO3, but hor, my LPS is all growing and opening. I am trying to reduce the NO3 to less the 10ppm, if possible thru the use of a non-suphur base denitrator.

[May&Bruce]

Well, water changes are important, not just for reducing nitrates but also for adding nutrients.

I used LFS water once, for the first water fill on our 3 foot tank. Had to carry 18 bags of water in my car. But I do not trust LFS water quality so now I always make my own.

Am currently doing a 10% water change fortnightly (60 litres change for a 5 foot tank).

[gift05]

i tested the NSW i buy from my LFS and am very happy with the results i see. Using a berlin system so i've got no bio balls no rings no DSB no nothin cept for a hunk o'junk of equipment in my sump.

right now, i get clear results of NO 3 from my salifert testkits so i'm not gonna argue with that nor do anything else cuz as long as i see my mandarin dragonet (its my benchmark of water qaulity) when i come home, i know life is good =)

[somebody]

clear results on NO3? which LFS?? haha

[May&Bruce]

in my opinion, buying salt water from LFS is just too risky. Look at the overall condition of most LFS's, and how many of them whwo have dead or dying fish in their tanks.............. too hit and miss. At least if you make your own, with DI or RO water you can be guaranteed water quality.

[gift05]

i have no idea of the shop's name but its in CCK farmart. He has this huge pond at the rear where you can leave unadopted fishes there haha and they thrive there! many pieces of LR in that pond as well that keep the water in great condition. oh and the water u buy comes from that pond

specific gravity of 1.023

calcium of 400mg/l

been using his water since i started cuz a ro/di unit is super ex and i'm actually just really lazy to mix salt and everything. just open the jerry can and whoala.

maybe if it turns u on even more, just go take a look at the fishes in the pond lo. if not doing so well, don't buy

[taylapong]

gift05: how much does he sell a jerry can for?

back to the topic of nitrate reduction.... so, when our livestock isn't doing well, what's USUALLY the main cause? Nitrates? Or something else? Cos i kept a tank in the past, and am currently in the process of planning for another one... but even then, the fish didn't do well!! I can't be THAT lousy right? I mean, nitrates were at about 50ppm, so i suppose corals wouldn't do as well as they should, but even fish??!! Is nitrate the main cause? or was there something else? The only thing that lived were damsels

Also, UNderstandably, if corals and fished look ok and survive, that's great... but, would the instead THRIVE in low nitrate situations? What's the verdict???

[May&Bruce]

In my short experience reefing, nitrate levels around 50 or so WONT kill fish. It could haven been ammonia, or more likely diseases introduced into your tank when you have added new live stock. Do you quarantine your fish, or at least acclimatize them first?

NEVER NEVER NEVER add any of the water in the bag into your tank when buying live stock.

[Gouldian]

From my limited experience, I believe it depends of the LS or Tank you are keeping.

If one is trying to have spectacular colors in your sps dominant tank. Then 0 nitrates is what one needs to achieve.

However, if one is simulating a natural reef biotope with fishes, clams, lps and some sps. Then a little nitrates will be apprecaites by the filter feeders.

2 cents.