I only have my filter on for 30mins a day 😅 i have some questions about air pumps

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Aquarium Advice Newbie
Apr 26, 2024
So about a year ago i bought a 6 gallon tank (25L) its 40x25x28 cm. I also got myself a water pump and a box filter (bcoz these type of filter are cheap and most common in my country). I get the cheapest water pump I could find 🤣.

now after I cycled the tank for 4wks w no fish, i got panda cories and they would always get sick then die. They would swim upside down b4 dying a day later. And I dont get why, I would get more panda cories from a different fish store and same result. 😅 ultimately since they kept dying, I gave up on the cories.

Now I added other fish along the way like guppies, mollies, etc..easy fishes. Some died but hey most lived lol, so I thought great. It must be the cories that are the problem, theyre difficult fishes. not an issue with my aquarium, again I cant believe how clueless I was a few months ago.

Then I finally figured out. It was the filter current that caused these fishes to die randomly. It was too strong for my small aquarium.

Problem is i cant afford water pumps with adjustable flow..so ever since a month ago, I just turned off my filter and only turned them on for 30minutes-1hour after I feed the fish.

Now I got more panda cories, they stopped dying but other fishes die 1 after another, im guessing bcs the water parameter is effed since the filters always off.

Water have gotten green, theres zero movement in the water so im guessing the good bacteria population are down and that mustve contribute to bad water parameter

Now I watched youtube videos that explains the importance of aerating my tank..and so I bought an air pump, maybe this will help in the meanwhile until I can get water pump with adjustable speed. I tried all kinds of hacks to slow down the output but it was still too strong.

With the aerator the flow is just right. I also put in some zeolite, bio stones, and sponge filter.. who knows maybe the fish will be fine with just the aerator, im gonna see if theres anymore sick or dead fishes in the upcoming days

Sorry for the long post above 😅 i have a few questions..in my case, how long should I keep the aerator on everyday? 12hrs? 24hrs? I have almost no plants in my tank, just a few cabomba and hornworts.

Also I saw in the leaflet that I should place the air pump above water? I did install an air valve in the tubing, so do I really have to put the machine above water? Cuz theres no place to do that, so id have to install a rack or something..

Thanks a bunch for the help btw..

Forgot to add, tanks population currently;
2 panda cories, 3 cory aeneus, 2 cory paleatus, 3 red nose tetra, 1 guppy female (other 2 guppies died 😅) and 4 celestial pearl danios. + 3 nerite snails and a dozen dwarf shrimps.
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Blimey, thats a lot to go through.

A 6 gallon tank is nowhere near big enough for the fish you where buying. Of the fish you mention only guppies should be kept in a 6g tank, 3 or 4 guppies at the most. Panda cories need to be in 15 to 20 gallons. Mollies maybe 30 gallons. Keeping fish in inappropriatly sized aquariums is very stressful, you cant maintain good water quality. Stress and poor water quality leads to ill health and fish dying. This is why your fish died.

You need the filtration on 24 hours a day 365 days a year. Apart from turning it off for short periods of time to do maintenance, it needs to be constantly running. Waste will be building up constantly, if its only on for an hour a day that means fish are swimming round in their own waste for the other 23 hours. And that 1 hour won't be enough to remove all the waste built up over the last 23 hours. Only running your filtration for short periods of time will cause poor water quality, again leading to fish dying.

A functioning filter will also aerate the water, so there isnt an absolute need for air pumps and airstones, but they can still be a benefit. Unless you are getting into complex CO2 injection systems for high demand plants, these also need to be running 24 hours a day.

Looking at your current fish you need at least a 20 gallon tank if you plan on keeping them all. 30 gallons would be better. If you arent able to provide a bigger aquarium, rehoming them would be the next best course of action and then getting fish more suited to your 6g tank. 3 or 4 guppies, or a single betta. Whoever is selling you these fish are being extremely negilgent. They should be making sure you have a suitable home before allowing you to buy fish.

If you cant or wont get a more suitable aquarium or rehome your fish there isnt much to do. Maybe changing water every 2 days will control water quality, but expect your fish to get sick with no real prospect of them getting better, and having a poor quality of life until they die. When they have all died off, you can look at keeping fish more suited to a small aquarium.
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I'm going to be kind. Find another hobby. Sorry but YOU are killing the fish. Save up some money read up on how to take care of fish get the proper tools then get the fish.
Aiken provides sound advice.

An additional way to get what you need would be to scour free postings where people need to get rid of tanks and stuff, because their kids don't care about the fish anymore or, their fish died and they gave up, or moving, etc. Another way is when people post for the items for sale, and they are moving, just email and say that you can come for the item for free to help them if it doesn't sell.

It sounds like you want the best for your fish ultimately and you can make changes to make that happen.

A 20G long tank would be a great size to start as an upgrade. They run about $22. from the store, no top or anything though. So finding a free tank would be smarter. Also places like a thrift store or Restore. If the new to you tank is dry and no fish, I would bleach it out (bathtub or shower area is convenient), to let the bleach water sit in the tank for an hour or so, about 5 TBL (74ml/4L) per gallon is more than enough to sanitize the tank (per CDC guidelines).

Cories are easy fish if they come to you healthy and you keep good water conditions. So do not give up on that dream, just wait for the best tank situation for them.

Also have you learned about the nitrification cycle and how the good bacteria keep your tank healthy? Check the link in my signature for the getting started article which explains it. <3
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