How many is too many ?

[Sblh]

Hi all !

I am new here and happy to join this forum
I have a tank running for 18 months. It's a shallow 55 gallon long (L60 inches, l20; H13) with lots of rocks, sand, some plants (not a lot, mostly anubias and bolbitis), 2 spots with leaf litters, 2 filters (Oase biomaster 850), a wave pump and an airstone.
About maintenance, i change 50% every week, clean both prefilters and pipes. They are fed with different types of pellets, repashy, vegetables, and frozen food like daphnia, artemia, etc.
With 6 panda garra and maybe 40? sewellia lineolata now.
I started with 7 sewellias, but it seems they decided to breed. I don't know really how many they are, i spot new babies all the time. They grow very well and seem very healthy They are so cute, i love them.
So yes, here is my question, how many is too many ?
I want to keep them happy and not crash my aquarium. But i have no idea (i am not a sewellia expert) how many is suitable.

Thanks a lot for your help !
I wish you all a good day

[NancyD]

Well, I have a 4ft 55g US standard sewellia lineolata tank. Mine breed & there are 2 or 3 survivors at most each year (I do nothing to help). I used to have stiphodon gobiesof a few species & some Vietnamese whiteclouds with them. All but 1 goby have died out over 12 years. I have 2 HOB filters rated at 300g/hour & a 1200L/hour powerhead (note the different measurements).

I kept panda garras in a different tank on a different US coast. I tried them once here (not in my sewellia tank) in California but it wasn't a success.

My sewellia grow VERY slowly, not adult size in 2 years. Do you know if you have wild or tank breed loaches? I've read I'm not the only 1 with slow TR sewellia.

So I can't answer your question but I'd like to know more about your tank...Maybe I could do better for my fish Sounds like your loaches are doing great! Can you tell me your water parameters please? Thanks!

[redshark1]

In the aquarium fish will die when water quality deteriorates.

Water quality deteriorates when nitrates and/or ammonia are too high.

Nitrates are too high when too much food is being added.

Too much food is added when there are too many fish to feed.

You have all the tools to manage this.

You should be aware of your parameters from doing your regular water tests. I use API test kits monthly, mainly the nitrate one. It is very easy to do.

Therefore decide what your limit is for nitrate and adjust your fish population, feeding and maintenance to sustain this level.

This is what I have done.

My nitrate has been around 5ppm for the last 20 years.

It is often said that nitrate is toxic when 40ppm is exceeded long-term but I haven't tested this personally.

I would therefore suggest you aim for nitrate below 40ppm but the lower the better.

[Sblh]

Hi !

Thanks for your answers

@NancyD
My sewellias are tank bred, i had two babies sewellias 13 months agos, and they still don't have their adult size so yes i assume they grow very slowly.
My parameters are :
PH 7, GH 6, KH 3.
Conductivity : between 370-400 μS.
Ammonia, Nitrites and Nitrates : 0
Temperature : I usually have 23 degrees Celsius. But with summer, it's more 26/27. I am not sure but maybe this temperature increase has triggered the loaches. The 2 previous babies were also born in this period so maybe i am not so wrong but i am not an expert

@redshark1

Yes, i am checking nitrates regularly, they are still at 0 for now, but i am aware i was far from being "overstocked" until now.
I usually prefer my tanks being understocked to not be on the extreme sides of maintenance and to guarantee a good water quality. This is why i am kind of overwhelmed with this sudden babies invasion

But yes, of course i will check regularly and see how my parameters fluctuate. I added a massive pothos and i have an empty 20 gallon long if needed, at least to keep them the time they grow up before giving them.
My concern was also about sewellia behaviour kept in large group, some people told me it will be war in my aquarium because they are too many, i am struggling to find any information about that for now.

Have a nice day

[redshark1]

Something is wrong if nitrates are zero.

There should always be nitrates in a cycled tank.

[Sblh]

I never had any nitrates in my tank, i know other people with this parameter. But with my population increasing, it will probably change.

[redshark1]

How do you explain the absence of nitrates?

A cycled aquarium with live fish present will be producing nitrates.

This is the basics of fishkeeping as I understand it.

[Sblh]

Yes, you are right and then, a part is consumed by plants, then, as I said, I change 50% of my water every week, use RO water (so no nitrates) and finally, until now, I did not have a lot of fish in my tank so, did not have a big source of pollution.

[NancyD]

I have a lot plants in my tanks too. I rarely test them any more but I see 0 nitrate often too. Sometimes with lesser water changes (vacations etc) I have tested as much as 5ppm. That is high for my tanks & a bunch of plants. I used to change more water when I had more fish & less plants. Now I don't worry or test as often. I seem to have reached a "tank stable" point.

Your sewellia breed! That's great! Your water tests look good, that's great too! You change a good amount of water every week, that's fabulous! Keep up your good fish keeping skills! I assume you feed a good quality & varied foods or you would not see all the breeding & growth you do see. I think you've gotten sewellia keeping down to just right!! Or at least my version of it. I don't want to go for maximum fry survival, a few are fine by me...

[redshark1]

I have two comments to make.

Nitrates are being produced. Therefore Nitrate cannot be zero. Perhaps you do not know how to test properly or your test is not detecting it.

Also, to not bother testing is to be complacent. Testing is done to pick up on problems before they affect your fish.

[NancyD]

Plants use nitrate, so given enough plants, nitrate can be low or even 0... If you use an API test kit you might see low #s. It depends on the plants & how fast they grow. Stem plants grow much faster than ferns + mosses...

[redshark1]

Regarding my first point.

Nitrates are produced continuously by the filter and pumped directly into the aquarium water via the filter outlet. Therefore nitrates in the aquarium water will be above zero all of the time even with growing plants present. The nitrates leave the filter and have to circulate in the aquarium water for a period of time before the plants can absorb them. Those that are absorbed are replaced by the continuous flow from the filter.