Confusion on feeding

Mmr1084

Feeder Fish
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Jan 10, 2022
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Good Morning,
I recently came into possession of two large bonded Oscar’s. I had been cycling a 100 gallon tank for some type of cichlids I hadn’t decided between red devils or blood parrots yet. But I knew I wanted one or the other. So I set up and cycled a 100 gal tank for four months. A week ago I was ready to finally purchase my fish. I went to my most reputable local aquarium store and as I walked in a couple was surrendering a pair of Oscar’s that they were told wouldn’t become larger then 5 inches. (Supposedly) they were stressed and not in the best shape. I took one look at them and said I could take them. I began to feed all fresh food like crickets,mealworms, and shrimp as well as Extreme Aquatic foods monster pellets. However while all my other water parameters are perfect my nitrates keep spiking between 20 and 30 ppm. I can only assume I’m feeding to often. But the info out there is so contradictory. How often, and how much should I feed? I do 20% water changes every five days and I have a well rated canister filter. I also vacuum out the waste every other day. What more should I be doing ? Sorry for the book. All advice is appreciated. Thank you for your time.
-Meagan
 
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Rocksor

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one meal a day and cut back to every other day until you can keep your nitrates below 20ppm delay at a minimum. Do a larger volume of water change and more than one water change a week as well

you will eventually find that sweet spot of how much water to change and when vs amiunt of food
 

FahakaPapa

Polypterus
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Dec 14, 2015
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If you're nitrates keep going up, you're not doing enough water changes. Increase those changes to 50%, or more, if you're feeding a lot. Use the nitrates to dictate your WC schedule.
 

Randles

Candiru
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Dec 3, 2021
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Its a bit of a balancing act in the beginning but you'll get used to how much is too much or too little. Also always remember a hungry fish is a healthily fish, well 99% of the time anyway. For now maybe up your maintenance while you are experimenting. One other thing is don't be fooled by the begging for food because Oscars are the masters at this. Please don't fall for those puppy fish eyes lol
 

duanes

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If you're nitrates keep going up, you're not doing enough water changes. Increase those changes to 50%, or more, if you're feeding a lot. Use the nitrates to dictate your WC schedule.
Agree
A 20% water change on a 100 gal tank once per week for 2 oscars (or any of that size cichlids) is pretty wimpy, especially if you over feed.
I try to do 30-40% water changes every other day for smaller cichlids in 300 gallons of tank, and sump.
And IMO canister filters do more to increase nitrates than not, because they are not normally cleaned regularly enough.
 

neutrino

Goliath Tigerfish
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Jan 22, 2013
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Agree with what's posted already. One add (besides don't feed too much) is that going heavy on live, protein and/or fat rich foods means more nitrates, all the more so if % of protein goes over what's optimal.

As far as canister filters go, it's mostly what I run and my nitrates are low. True, some filter types are easier to clean, but there's no reason canister filters should produce more nitrates than other filter types, though some canisters are easier to clean/maintain than others. Media setup can affect this also, some filters out of the box are set up almost backwards, but if mechanical filtration and the bulk of water polishing is at the first stage(s) of water flow it keeps most of the junk trapped there and helps your bio media stay cleaner and more efficient. Nitrates with any filter depends on stocking and feeding, filter capacity, how a filter's set up with media, etc. and your routine for keeping them reasonably clean. It can take some tinkering to find the sweet spot for all of this in a particular tank. I feed moderately and do pretty big water changes, even without heavy stock, for me filter cleaning works itself out to vary on different tanks.
 

esoxlucius

Alligator Gar
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Dec 30, 2015
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Welcome to the forum.

The problem you have is very very easy to remedy, and the guys have pointed you in the right direction with some good advice.

Those two big Oscars in that size tank will put out quite a bio load, your nitrate readings are proof of this. And if you overfeed then you're simply adding to the problem.

It's ok having a high bio load, nothing wrong with that, but you need to make sure you put the effort in, by way of water changes, to keep that nitrate in check, or it will just rise and rise and rise, as you are finding.

The biggest problem you have is those Oscars will beg and beg and beg, as if they're starving to death. Do not fall for their little tricks.

Good luck.
 

Mmr1084

Feeder Fish
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Jan 10, 2022
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Thank you all so much for your advice as well as the warm welcome. They do beg ! So of course I thought I was feeding to little. I thought a 6 and 8 inch Oscar was an ok bio load for 100 gal tank. The canister filter we have is one that’s for 250 gal so I thought it would be ok. I’ll increase my water change amount and feed every other day till I get a good balance. I did a heavy water change and the nitrates have dropped below 10ppm. I was afraid to do to large of a water change too often for fear of causing instability. I think we will be looking into an RO system, our water is very soft already so I usually have to re mineralize it anyway. I’ll test everyday till I’m sure I’ve got he right combo. We have also discussed moving to a 180 gal within the next year. Would that be acceptable? Should we go larger ?
 

Mmr1084

Feeder Fish
MFK Member
Jan 10, 2022
8
6
3
32
one meal a day and cut back to every other day until you can keep your nitrates below 20ppm delay at a minimum. Do a larger volume of water change and more than one water change a week as well

you will eventually find that sweet spot of how much water to change and when vs amiunt of food
Thank you so much. I’ll definitely increase the water changes and try to find the correct balance between feeding and cleaning.
 
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Mmr1084

Feeder Fish
MFK Member
Jan 10, 2022
8
6
3
32
Welcome to the forum.

The problem you have is very very easy to remedy, and the guys have pointed you in the right direction with some good advice.

Those two big Oscars in that size tank will put out quite a bio load, your nitrate readings are proof of this. And if you overfeed then you're simply adding to the problem.

It's ok having a high bio load, nothing wrong with that, but you need to make sure you put the effort in, by way of water changes, to keep that nitrate in check, or it will just rise and rise and rise, as you are finding.

The biggest problem you have is those Oscars will beg and beg and beg, as if they're starving to death. Do not fall for their little tricks.

Good luck.
Thank you for your welcome. Yes they always “ask for food” it’s much different from my community tank that just know when feeding time is.
 
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