The Planted Tank Forum banner

Excel nitrite spike

597 Views 21 Replies 4 Participants Last post by  emoore3
I’ve been using flourish excel to keep some black beard algae at bay. It’s been doing a decent job of that but the last few weeks after my 50% water change there is a nitrite spike. I see the fish gasping the next morning after adding 2 capfuls of excel in 25 gallon tank. Has anyone else experienced this? Normally my nitrate is 0 and the tap water is 0. But the spike pushes it to 0.5 to 1ppm.
1 - 20 of 22 Posts

· Administrator
Joined
·
18,212 Posts
I’ve been using flourish excel to keep some black beard algae at bay. It’s been doing a decent job of that but the last few weeks after my 50% water change there is a nitrite spike. I see the fish gasping the next morning after adding 2 capfuls of excel in 25 gallon tank. Has anyone else experienced this? Normally my nitrate is 0 and the tap water is 0. But the spike pushes it to 0.5 to 1ppm.
Nitrite or nitrate? You mention both.

Nitrate isn't going to harm anything at those concentrations. But a nitrite spike means you're somehow killing off beneficial bacteria to the point that it can't process all of the ammonia in your system.

What's your ammonia test detect?
 

· Registered
I have 10 tanks ranging from 7 gallons to 125 gallons.
Joined
·
55 Posts
My Excel directions say 1 cap/50 gallons for all treatments after the first one. It sounds like you may be overdosing?
Or, maybe it’s your tap water, since it’s always after a water change. Have you tested that?
 

· Registered
Joined
·
298 Posts
Discussion Starter · #5 ·
My Excel directions say 1 cap/50 gallons for all treatments after the first one. It sounds like you may be overdosing?
Or, maybe it’s your tap water, since it’s always after a water change. Have you tested that?
Yeah I’ve been doing just 1 capful after the big water change. I backed down to 2 capfuls after a water change and still having issues. Tap water tested at 0 nitrite.
 

· Registered
Joined
·
13,346 Posts
Sorry it’s nitrite. I wouldn’t worry if it was nitrate. I expect those. Ammonia reads 0.
A capful is 5 ml.
10mL / 20 gal is a pretty minimal dose...to me.
1mL/ gallon is pretty normal for treating bba.
I routinely use 30+ ml glut in my 40b.


How do you treat your exchange water?
It doesn't appear to be glut related.
Maybe a change by your water service?
 

· Registered
Joined
·
13,346 Posts
The " broken" step...
Subsequently, nitrite-oxidizing bacteria (e.g., Nitrobacter or Nitrospira species) are responsible for the final oxidation of nitrite to nitrate, through a reaction catalyzed by a molybdenum-containing nitrite oxidoreductase (MoNiOR, described in section 3.3.1). These bacteria are chemolithoautotrophs, phylogenetically heterogeneous, that derive energy from the nitrite oxidation to nitrate, in a strictly aerobic process, where all of the carbon needs can be satisfied with carbon dioxide assimilation (via Calvin cycle). (97-103) Nitrite oxidation “closes” the nitrification process and is believed to be the principal source of nitrate under aerobic conditions.
Still think the answer lies in your water change.
Maybe you ran out of " moly".. 🙂
Chlorine, chloramine, low pH, low O2 can all inhibit or kill your bacteria.
Since it is a 2 step process with 2 different groups of organisms having one step function while the other doesn't is not out of the realm of possibilities.
I personally only had one nitrite spike in a fully cycled and usually old tank.
I had no clue as to why.
Seachem Prime and small water changes got me through it.
Could be as simple as an ammonia spike efficiently cleaned up but overloading step 2.
Something dead may do that.
 

· Registered
Joined
·
298 Posts
Discussion Starter · #11 ·
Could be the water change but water tests as 0 ammonia, 0 nitrite, low nitrate. I always use prime to treat the water. Guess I could try using RO water as I do have a system for my reef tank. I’ll see how this Saturdays water change goes without excel. If I still have issues I’ll switch to RO water.
 

· Registered
Joined
·
298 Posts
Discussion Starter · #12 ·
The mystery continues. Didn't use Excel for a week and changed 50% water yesterday. Still got a nitrite spike of 0.5ppm. I've been running some experiments this morning and no combo I create produces any nitrites. Here are my combos so far:

Tap water only: 0
Tap water w/prime aged 24 hours: 0
Tap water, prime, thrive ferts: 0
Tap water, prime, excel: 0

Not sure what is causing the nitrite spike. Any suggestion for more experiments?
 

· Administrator
Joined
·
18,212 Posts
The mystery continues. Didn't use Excel for a week and changed 50% water yesterday. Still got a nitrite spike of 0.5ppm. I've been running some experiments this morning and no combo I create produces any nitrites. Here are my combos so far:

Tap water only: 0
Tap water w/prime aged 24 hours: 0
Tap water, prime, thrive ferts: 0
Tap water, prime, excel: 0

Not sure what is causing the nitrite spike. Any suggestion for more experiments?
Does your water supplier treat with chlorine or chloramine? Chloramines won't evaporate by "aging" water and if you're treating it with Prime and allowing it to sit for 24 hours prior to adding it to the tank, it's likely that it's no longer neutralized at that point and allowing for an ammonia/ammonium spike that's higher than your system can process. (Since you say there's 0 Ammonia detected in your tap water, I'm assuming it's chlorine.)

Do you treat your water change water with Prime in a container before adding it to your tank? I find that's helpful and means you can use less product.

Have you tried increasing your dosage of Prime? It's possible something is off with your water supply. I've found my local water company occasionally has instances where the amount of chloramine they add is extreme compared to other times of year. Any time I use tap, I double or trip dose Prime/Safe to make sure I'm getting everything. It's so unreliable I tend to use remineralized RO for everything.

Are you absolutely certain nothing has died in the tank that you're unaware of?

Have you conducted any filter maintenance? Removed media? Done any tank deep cleaning? Removed anything from the tank that would have meant a loss of bacteria on surfaces?

All those questions aside, how open are you to ICP testing your tap & tank water if this doesn't end over the next week or two?
 

· Registered
I have 10 tanks ranging from 7 gallons to 125 gallons.
Joined
·
55 Posts
Also, and this is a completely wild guess, is it possible that you somehow have a bad bottle of Prime and it isn’t dechlorinating? Is that possible?
 

· Registered
Joined
·
298 Posts
Discussion Starter · #15 ·
Thanks for the reply Kwyet. Here are my answers to your questions.

Doesn't matter if it's fresh tap water (no prime), fresh tap with prime, aged tap no prime, aged tap with prime all the tests show 0 nitrites. I have also tried a new bottle of prime and got the same results with the tap water and the tank (0 nitrite in tap, 0.5ppm nitrite in tank day after water change) Haven't changed out the sponges in a few weeks. I always replace the filter floss every water change.

Pretty sure nothing has dies, I'm sure nitrite will read 0 tomorrow and will be that way until I change water on Saturday. If this continues I'll look at an ICP test for tap and tank water.
 

· Registered
Joined
·
298 Posts
Discussion Starter · #16 ·
Tested the tank water last night (Monday) and came back 0 nitrites. So I'm at a loss at what could be causing the spike right after a water change. This saturday I'll test right after the water change and every few hours after.
 

· Registered
Joined
·
298 Posts
Discussion Starter · #17 ·
Well another 50% water change and another nitrite spike. Tested the tank everyday fir the past week and 0 nitrites. Tested the new water before it went into the tank and 0 nitrites. Guess the only thing I can do is reduce the amount of water changes. I’m at a loss.
 

· Registered
I have 10 tanks ranging from 7 gallons to 125 gallons.
Joined
·
55 Posts
I would try adding some QuickStart or similar with every water change and also increasing your dosage of Prime as Somewhat Shocked mentioned above, since it seems something is hampering your cycle each time. It might not fix it, but it wouldn’t hurt to try it.
 

· Registered
Joined
·
298 Posts
Discussion Starter · #19 ·
Might try turning off the co2 for a day after a water change. I’ll also try more prime and do smaller water changes.

So I’m going to start using remineralized RO for water changes. Any good remineralized recipes?
 

· Registered
I have 10 tanks ranging from 7 gallons to 125 gallons.
Joined
·
55 Posts
Won’t turning the CO2 off cause instability and problems with your plants? Is there some reason that might help with a nitrite spike? It doesn’t make sense to me.
I read a post about DIY remineralization, but I haven’t been able to locate it again. I think it was from somewhatshocked and it was tailored to Bee shrimp. Maybe he’ll come back and post it, or you might be able to find it. Good luck!

Edit—I found it!
 
1 - 20 of 22 Posts
Top