if I top up 20% of my tank capacity each week, do I need to change water?

[Bayinaung]

I recently got a mature nano 10 gallon tank from an enthusiast. I noticed that in my apartment the water (open top, good flow) top up is coming to about 6-7 liters a week or about 1.6-1.8 gallons. That's more than the 10% water change per week that's recommended. If I'm topping that much, how often should I change water?

 

[Fish noob]

Yes, you should still do water changes because the fish waste is not evaporating.

 

[Fish noob]

I have a 60 gallon and change 10g every week.

 

[Phranque]

Top-off are not water changes...... And you are topping off with fresh (unsalted) RODI water, correct??
Top-offs only replace the evaporated water to maintain proper salinity. Water changes remove waste from the system and replenish valuable nutrients to the water column that are consumed by corals.

 

[Bayinaung]

Yup. ok. that makes sense. I'll keep doing water change. I read on a magazine site some people do 100% water change in their nano tanks. I have no fish (yet) in it. mostly crabs and snails and some tiny corals.

 

[Phranque]

With just snails & crabs, you have some bioload, but very little.... a 10% weekly water change should be plenty.
Do your research carefully before adding fish..... there is a very limited assortment of what can comfortably fit in a tank that small. Probably going to be a small goby, and that's about it....

 

[Bayinaung]

Thanks. I'm not ready to add fish just yet. I think I'll be adding more corals though. The anemone and crabs are keeping me busy Emerald crab loved the boiled spinach I put in the tank.

 

[Phranque]

Keep a very close eye on your corals. No flat crab is truly reef safe, it's just that the emerald is the least evil of them. If it does get a penchant for coral, you'll need to remove it. There are a bunch of stories on here of people having emeralds for many months with no problems, then all of a sudden it takes to eating a whole bunch of zoas or other soft, fleshy corals.

 

[Bayinaung]

Darn really? were they feeding the crab? give it vegies fruits seaweed or just letting it scavange for left over fish food?

 

[Bayinaung]

Do I need to have a fish in a nano when there's anemone, corals and crabs?

Someone asked if I had any bioload in my nano and I said anemone. They thought I still need fish in there. This is a mature 10 gallon nano. I did have fish before, now just the anemone. Thoughts?

 

[Phranque]

Darn really? were they feeding the crab? give it vegies fruits seaweed or just letting it scavange for left over fish food?

Most likely leaving them to scavenge as a member of the CUC and they got hungry.....

Someone asked if I had any bioload in my nano and I said anemone. They thought I still need fish in there. This is a mature 10 gallon nano. I did have fish before, now just the anemone. Thoughts?

If you've got inverts in there, they poop too.... it may not be very much, but it's enough to maintain some beneficial bacteria. The only thing to note is that the amount of BB adjust to the bioload that you have, so if you suddenly add a larger load like a fish, you may see a mini spike in ammo & nitrites until the BB catch back up.

 

[Bayinaung]

So your answer sounds like, I should add a small fish...

 

[Phranque]

You tank will do OK without one, but I'd personally have a small goby in there just 'cause they're cute to watch...... your choice.

 

[Bayinaung]

Ok thanks. I'll begin researching on gobies... I'll add a clown when the anemone is bigger.

 

[Phranque]

I'll add a clown when the anemone is bigger.

Sorry, but that tank is way too small for a clown.... Even for the smallest clowns, you need a minimum of 20g, preferably 25 to 30. With a pico that size, one fish is about all you want.....

 

[Michaelbknudsen]

Sorry, but that tank is way too small for a clown.... Even for the smallest clowns, you need a minimum of 20g, preferably 25 to 30. With a pico that size, one fish is about all you want.....

You can keep a clown for a long while (year or two) if you'll upgrade or transfer it to another tank. Just keep an eye on parameters and get a tank bred juvenile Ocellaris Clown, which is one of the smaller varieties. Research more, and you'll see it's fine.

 

[Phranque]

You can keep a clown for a long while (year or two) if you'll upgrade or transfer it to another tank. Just keep an eye on parameters and get a tank bred juvenile Ocellaris Clown, which is one of the smaller varieties. Research more, and you'll see it's fine.

In all attempts to maintain civil conversation, I'll word it as being ardently adverse to this particular practice. You're purposely placing a fish into an enclosure that you know it will out-grow, causing discomfort & stress until it's moved, and then causing even further distress by having to acclimate it to a new home, when it could have been placed there in the first place to live a long, healthy, happy, stress-free life.

 

[Bayinaung]

Alright, let's not argue about a hypothetical fish being added to a nano. I'm not planning on adding any angels for instance. Both you have good points. Anything I do will be to scale. If we want to be truly ethical and ecologically sensitive we shouldn't be having this hobby at all because it IS destroying corals around the world not to mention the carbon footprint on this? we might as well NOT do it and support keeping local fishes only. This IS a guilty pleasure, however you want to justify it.

Now yeah I'm soon building a double 55/65 gallon tanks with mangrove shallow water type "sump" if you will that I will cycle for at least six months before attempting to put any livestock in. I love mature tanks. They are just so much more stable. This is my project for the summer.

I have kept fresh water tanks for 20 years and know the value of cycling and eco system of enclosed water tanks. I just don't have a monitor with probes sitting in the tank measuring every measurable every second. I have an instinct about tanks, and fishes. So whatever fish I add, will be fine. Peace!