Nitrate spike vs food

[KevinB]

Question, noticed a change in my tank in the last week.

Error in title. I mean NITRATEs.

I have fed my 4 < 1yr convicts (3-4") small Omega convict pellets and flakes for many months, and they have very routinely put out about 5ppm of Nitrates per week so a 15 gallon water change keeps it at 5-10 ppm for months. Last week or so, my wife began feeding them dried brine shrimp vs the pellets. The Nitrate jumped 20 in one week. I am pretty sure the food change is the root cause, but brings up the question as to what is the best diet for them. I think I have seen some growth in the last 2 weeks. I can change more water if the shrimp is a good diet as well.

My wife feeds them 3 times a day which is probably a bit much, but it's small portions.

Thanks, kevin

 

[Delapool]

I'm not sure with cichlids.

I had thought a varied diet was good for fish in general and also feed brine shrimp (frozen) as roughage. This makes a bit of a mess but I have a planted tank so have to dose nitrates anyways.

 

[PB_Smith]

why are you even concerned about 20 ppm of nitrate?
that is essentially nothing.
fish can tolerate much, much higher levels than that and a lot of the info I have read actually leaves the impression that there is still debate whether nitrate at the levels we encounter is of any concern at all.


20 ppm of nitrate, pffff, not even worth a second thought.


WHAT you should be concerned about is that indicates that the ammonia and nitrite also spiked, but most likely your system is established enough that you never notice.
Remember, nitrate is an indicator of overall nutrients entering the system and the subsequent breakdown of them.


The best diet for any critter is a varied one, so why not both feed pellets and brine shrimp?

 

[KevinB]

why are you even concerned about 20 ppm of nitrate?
that is essentially nothing.
fish can tolerate much, much higher levels than that and a lot of the info I have read actually leaves the impression that there is still debate whether nitrate at the levels we encounter is of any concern at all.


20 ppm of nitrate, pffff, not even worth a second thought.


WHAT you should be concerned about is that indicates that the ammonia and nitrite also spiked, but most likely your system is established enough that you never notice.
Remember, nitrate is an indicator of overall nutrients entering the system and the subsequent breakdown of them.


The best diet for any critter is a varied one, so why not both feed pellets and brine shrimp?

I didn't say it was 20. I said it rose 20-30ppm in one week which is up from 3-5 ppm per week "gain"

Before in my 37, I could do a 15 gallon change 1/week, and it would keep it between 5-10 which is great. With this new "nitrate gain rate" I would have to change 30 gallons per week. Even if I move up to the 75 gallon tank I am looking at, it's still 30 gallons per week of water changing. Otherwise, the tank is always gaining on you in nitrates. You have to change the water based frequently enough to keep the nitrates in a healthy range.

The change was due to the food, so I wondered if they should have been fed this much all along or if I am now overfeeding with the shrimp in the diet and need to cut back if the shrimp is part of the diet. I was still planning to do a 15-18 gallon per week water change, but in a 75 gallon tank, that's 20% water change.

Kevin

 

[PB_Smith]

your still worried over something that really isn't that serious at all.
nitrate levels such as you are having are perfectly safe for freshwater fish and trying to get them down to 5-10ppm could cause more harm than good.
Often folks begin chasing numbers and cause more problems.


The idea of high nitrate being detrimental applies mainly to reef tanks with corals and invertebrates that are much more sensitive to nitrate. The same rules and concepts do not apply to freshwater.
For example high nitrite is pretty detrimental to freshwater fish, yet research suggests that it is relatively safe for saltwater fish and can be tolerated at much higher levels.
Ideally we all want pristine water, but that isn't realistic for many reasons.
Again, nitrate is relatively safe for freshwater fish until you start climbing past 100ppm and even then the effects I believe are stunted growth.


do you use any type of chemical filtration? Chemi-Pure might help.

 

[KevinB]

your still worried over something that really isn't that serious at all.
nitrate levels such as you are having are perfectly safe for freshwater fish and trying to get them down to 5-10ppm could cause more harm than good.
Often folks begin chasing numbers and cause more problems.


The idea of high nitrate being detrimental applies mainly to reef tanks with corals and invertebrates that are much more sensitive to nitrate. The same rules and concepts do not apply to freshwater.
For example high nitrite is pretty detrimental to freshwater fish, yet research suggests that it is relatively safe for saltwater fish and can be tolerated at much higher levels.
Ideally we all want pristine water, but that isn't realistic for many reasons.
Again, nitrate is relatively safe for freshwater fish until you start climbing past 100ppm and even then the effects I believe are stunted growth.


do you use any type of chemical filtration? Chemi-Pure might help.

I don't think you understand what I mean by rate nitrate change, nor understand a steady state process. I never said I am trying to keep it between 5-10. I said that to keep my tank at any steady state I would need to change 2x the water per week than what I was changing before the diet change. This would be the case if my average was 10 or 100. Your rate of change still dictates the water change frequency. I was simply asking if it was common for this to be tied to diet and type of food.

I ran an experiment and figured it out for myself. I went back to just pellets and flakes and the nitrate gain per day went back to normal. My tank right now is actually 30ppm.

Given that a constant nitrate level requires a constant or regular change frequency, I can't see where it matters if you keep it at a steady state of 10 vs 100. It's better for the fish, and the change frequency doesn't change.