Curious… do you cover your tanks???

So I have had fish that required covering in the past, but most of my tanks involved growing plants out of my aquariums… when we moved here 20 ish years ago, I built in most of my tanks… this allowed me tank to ceiling walls over my tanks… I still grew plants out of them, but they were only visible to me, behind the tanks… I got out of the hobby for a decade or two… and recently started them up… new baby plants now… I do have a few jumpers, & a plexiglass sheet hinged to the ceiling gives me a complete wall surroundings most tanks have 14 - 18” walls tight around the tops of 3 sides, leaving the back open, except for the hinged back I can add as needed

I do, I don't have any real jumpers but it gives me peace of mind! My cover is a bit ugly, it's just the black plastic lid that comes with the aquarium, I know I could get a clear plexiglass one but not sure I can be bothered with the faff!

Hooded tanks for the win

I have a lid and cover glasses - it's a custom built tank and that's the way it was made.

Humidity....

I cover most, but because of emergent plants, there are openings. A lot of my tanks aren't filled to the top because my killies do jump, although it is rare when there are big leaves overhanging the water.

There are two reasons to cover - jumpers and evaporation. There are two reasons to not cover - plants and evaporation. Do as you do and don't do as you don't do.

… I don’t think there is a right or wrong answer, just depends on your fish… even when I had plants growing out of my tanks, and most weren’t covered… the tanks that had my 24” pacu, and 20 Arrowana, were covered… in fact the pacu tank got a weighted cover, one evening he jumped up, knocked his tank cover off, and began flopping on the floor… fortunately he wound up pushing the hollow core interior door closed, and was flopping against that… Mrs and I were freaked out… sounded like an intruder was trying to break down the door… I got a hold of him( quite challenging, he was 18” at that time and probably went over 10 lbs. )… I started adding 4-5 lbs. of weight to the cover, and that worked, until a couple years later, at 24” he knocked it off again, only this time we were out of town for the weekend, and that was the end of him…

I don’t have anything like that now..

I went to feed my betta today and he jump right out the tank. Picked him up off the floor and put him back in and he ate then. Definitely a cover on that tank.

I do have a small 5 gallon Tetra Cresent tank with 2 young guppy and don't have a lid on it because the light I have for it wouldn't work. I have had more grown guppy I bought from the store jump out of it before however so if I were to put larger fish in there it would have to lower the water level or put the lid on.

I also have a 10 gallon that I borrowed the lid from for quarantine tank with some zebra danio and corydoras and haven't had an issue with them jumping out really. This tank does have hornworn floating at top of water and other floater plants so that does help a bit as well.
But my other tanks all have lids because I don't trust some of the fish to not jump out.

I usually cover my tanks to reduce evaporation and prevent jumping, as others have said. With emergent vegetation, I will usually still use a cover with openings in it.

all my tanks have plants growing out of them. One has a plastic greenhouse over it for humidity so I can grow epiphytes.The others don’t have covers.

I have cover on 5 out of my 6 tanks mostly due to the fish/humidity, but also, because of dog hair. The sixth tank I didnt want a cover, cause of light that is too far above, and behold, saw the dog drinking from it once or twice. Would not recommend!
I usually go to local glass shop and ask them to cut me a piece that matches measurements with 1 cm more on each side and or a cut corner for cables/hoses

Most of my tanks don't have a lid. I like the look of an open tank.

In the 3rd picture I posted, I have some emergent lucky bamboo, that is an acrylic tank, which has a top with holes cut for filters, and one of the old style heaters, so I inserted a bundle of the bamboo from the top into the heater hole, as I don’t use that style of heater anymore… I’m trying something different here, as I usually burry the roots in the substrate… these I left hanging, with the roots exposed… there is an under gravel filter, and 2 big old ( had them 20 years ago previously, and they still running ) hang on tank filters, the only media are some smaller slotted planters filled with ceramic media, to hold the roots of some baby monstera plants, the filters move and agitate the water for air

Definitely covered for me.

I have lost a lot of chili rasboras due to jumping. Certainly with nano tanks (here in the UK anyway), it seems you can't really get any that come with a proper hood and decent lights, so if you want a decent light unit you have to either go open top or just have a glass sheet cover. I have a glass sheet covering my chili rasbora tank, but I have still had jumpers through tiny gaps around the sides. I am going to be making some better covers myself and if they turn put okay then I may post details in another thread when done.

Additionally, I did a water change once and was lazy in clearing up afterwards, so I left the water change bucket with a couple of inches of surplus water in my lounge where the tanks are for a few days. The room isn't really used very much, It's just me viewing/attending to my fish or my son playing his Xbox in there. The amount of stuff floating on the surface of the water in the water change bucket after a few days was shocking. If my tanks were open top all that stuff would be in my tanks, even without me noticing. It seems to be mostly carpet fibres, although we have never noticed any issue with this previously.

Personally, I will never keep any open top tanks.

One of my Granddaughters has an open top twenty high . I have never had anything but covered aquariums but hers is nice . The water level is down about two inches and you can hear the outside power filter gurgling and splashing and the sound is tranquil and soothing . All she has is guppies and Ramshorn snails so she’s never had a jumper . She is good about her water changes so evaporation has never been a problem for her . It’s fun to watch the fish from above . I would like to try it but I’m old and set in my ways and if I did remove one of my covers I’d probably set it somewhere and accidentally break it . That’s the kind of luck I have .