Nitrate spike

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pdw1731

Aquarium Advice Activist
Joined
Aug 31, 2011
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125
Location
Waldorf, MD
Ello all

I did a 50% wc yesterday and , well, had the urge to test my water this morning. My ammo and -trites were both 0 but my -trates were way up there at 40+. I did another pwc tonight and retested the water. maybe it was my light but i swear my reading was actually worse after the wc. I beat my bottles like a rented mule and am going to do a larger % wc in the morning. I'm sure the pwc's will eventually work out the kinks but i'm stumped as to what caused the spike to begin with. I haven't done anything out of the ordinary lately. Any ideas, generally speaking?
 
Do you have fish in the tank or are you cycling? Have you tested your tap water for nitrates?
 
Do you have fish in the tank or are you cycling? Have you tested your tap water for nitrates?

I have fish in the tank buy my tanks been cycled for a couple months now. Mini-cycle?

Yep, tested for nitrates, nothing out of the ordinary there.

I'm doing another pwc this morning and see what gives. Dunno, maybe it's just on of those "isht happens and there's really no good explanation for it" events.
 
Do you have messy fish with a heavy bioload? Dirty fish can make the nitrates rise fast.
 
Do you have messy fish with a heavy bioload? Dirty fish can make the nitrates rise fast.

just tetras in my 29g...but i am at adult capacity. But, i may be wrong, but i thought that being at of over capacity would only affect the ammo? My ammo and trites are both at 0. I'm going to monitor this for a few days then move some of my fish to another tank to see what that does.

The bad part about learning this hobby is that the fish sometimes end up being the ones that pay for our ignorance and mistakes.:(:(
 
Nitrates will always be present in a cycled aquarium; the rate at which they rise is usually determined by the bioload in the tank. So if you have a lot of fish in a tank (or are overstocked, over feeding, etc) the nitrates will rise faster. Nitrates are only removed through water changes. What is your normal water change schedule? If a 50% water change per week isn't enough to keep the nitrates <20 between water changes then you'll have to do two pwc per week. So just adjust your water changes based on your nitrates. I'd also test your tap water for nitrates as well as the pwc you did should have taken some of the nitrates out unless you didn't do a large enough water change or unless your tap water has nitrates.
 
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It sounds like you need to do water changes till you get the nitrates down. Make sure you're not overfeeding your fish.
Often high nitrates will bring your pH down. If you are doing large PWC's you need to be careful of pH Shock. In a low pH scenario, it would be better to do more smaller PWC's than real large PWC's to allow the fish to acclimate to the higher (new) pH levels.
 
You could have rotting plants, rotting food, or a decaying fish somewhere in the tank causing a spike. Ideally you shouldnt see an ammonia spike in a well seeded tank. If the bioload increases you may have a slight mimicycle as the bacterial colony grows to consume the waste, but then you would see an increase in nitrates as a result.
 
Nitrates will always be present in a cycled aquarium; the rate at which they rise is usually determined by the bioload in the tank. So if you have a lot of fish in a tank (or are overstocked, over feeding, etc) the nitrates will rise faster. Nitrates are only removed through water changes. What is your normal water change schedule? If a 50% water change per week isn't enough to keep the nitrates <20 between water changes then you'll have to do two pwc per week. So just adjust your water changes based on your nitrates. I'd also test your tap water for nitrates as well as the pwc you did should have taken some of the nitrates out unless you didn't do a large enough water change or unless your tap water has nitrates.

about 50% every Sunday. I'm doing another on now just to see what happens.
 
It sounds like you need to do water changes till you get the nitrates down. Make sure you're not overfeeding your fish.
Often high nitrates will bring your pH down. If you are doing large PWC's you need to be careful of pH Shock. In a low pH scenario, it would be better to do more smaller PWC's than real large PWC's to allow the fish to acclimate to the higher (new) pH levels.

checked pH...holding steady at 7.5 both before and after wc
 
You could have rotting plants, rotting food, or a decaying fish somewhere in the tank causing a spike. Ideally you shouldnt see an ammonia spike in a well seeded tank. If the bioload increases you may have a slight mimicycle as the bacterial colony grows to consume the waste, but then you would see an increase in nitrates as a result.

Well, i finally have a handle on my feeding sched. I alternate 1x/day and 2x/day fedding with a fast on Saturdays. No food out of the ordinary as far as i can remeber (sad i know, i can't remember what i fed them since Sunday....sheesh)
 
Not to sound picky but y use prime which is for newer tanks and/or change in bio load, instead of stress coat,or sum other regular dechlorinator?
 
Not to sound picky but y use prime which is for newer tanks and/or change in bio load, instead of stress coat,or sum other regular dechlorinator?

Been using it since day one and never knew there was a difference other than brand preference.
 
Interesting info on Prime and Nitrates.

From their FAQ's page; Seachem. Prime FAQ

Q: How does Prime make a difference in reducing Nitrates?

A: The detoxification of nitrite and nitrate by Prime (when used at elevated levels) is not well understood from a mechanistic standpoint. The most likely explanation is that the nitrite and nitrate is removed in a manner similar to the way ammonia is removed; i.e. it is bound and held in a inert state until such time that bacteria in the biological filter are able to take a hold of it, break it apart and use it.

Two other possible scenarios are reduction to nitrogen (N2) gas or conversion into a benign organic nitrogen compound.
I wish we had some more "concrete" explanation, but the end result is the same, it does actually detoxify nitrite and nitrate. This was unexpected chemically and thus initially we were not even aware of this,

however we received numerous reports from customers stating that when they overdosed with Prime they were able to reduce or eliminate the high death rates they experienced when their nitrite and nitrate levels were high. We have received enough reports to date to ensure that this is no fluke and is in fact a verifiable function of the product.
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I would not mis-interpret this as a fix for high nitrates but I'm thinking Prime is helpful if your tap has nitrates in it. As least I'm hoping it helps... lol.
 
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