Filtration advice for a 48-gallon tank

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donny5
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Filtration advice for a 48-gallon tank

Post by donny5 »

I've been looking into getting some small Pseudotrophy cichlids for my 48-gallon tank. They max out at 3 inches, so I think it's doable. I've done a lot of research and I know I'll need to overfilter the tank. Would two large HOB filters work for this, or is there a better setup you'd recommend? I'm thinking of keeping 2 males and 5 or 6 females, with a bunch of hiding spots for them.

I know I can overstock the tank a bit, up to around 18 fish based on the 80% rule, then cut that in half. But I'm wondering if 8 mbunas would be too few for a tank this size?

My main concern is that I want to be able to do weekly water changes. If I have to do them every 3 days, it's just not gonna work for me, especially if I go on vacation. So I need a setup that can handle that.
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TankWarrior
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Re: Filtration advice for a 48-gallon tank

Post by TankWarrior »

I'm a bit skeptical about the need for overfiltering. Why not just set up the tank and do regular water changes? I mean, filters just clean the water, but they're not a substitute for a good water change.

If you keep the bioload low, you can get away with changing half the water once a week. I'd say, if you're looking to keep a small school of fish like the Pseudotrophy cichlids, and you're not overfeeding, you can easily manage with weekly water changes.
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Tigger
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Re: Filtration advice for a 48-gallon tank

Post by Tigger »

donny5 wrote: Thu May 22, 2025 3:22 pm I've been looking into getting some small Pseudotrophy cichlids for my 48-gallon tank. They max out at 3 inches, so I think it's doable. I've done a lot of research and I know I'll need to overfilter the tank. Would two large HOB filters work for this, or is there a better setup you'd recommend? I'm thinking of keeping 2 males and 5 or 6 females, with a bunch of hiding spots for them.

I know I can overstock the tank a bit, up to around 18 fish based on the 80% rule, then cut that in half. But I'm wondering if 8 mbunas would be too few for a tank this size?

My main concern is that I want to be able to do weekly water changes. If I have to do them every 3 days, it's just not gonna work for me, especially if I go on vacation. So I need a setup that can handle that.
I've got a 48x18x18 tank with 7 cichlids, all about 3" long. Tydal 75 HOB filter does the job. The cichlids love digging and stirring up the sand substrate, and the HOB picks up all the detritus - no need to vacuum.

Don't get why overfiltering is a thing - doesn't reduce nitrate levels. Live plants are the way to go, though. I've got large rocks around the base of the plants, and the cichlids leave them alone.

Weekly or 10-day water changes work for me - around 30% each time. If I'm away, it might be 3 weeks before I change the water again. But changing water every 3 days? No thanks, I'll find another hobby.

Can't help with the number of fish, though.
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donny5
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Re: Filtration advice for a 48-gallon tank

Post by donny5 »

Tigger wrote: Thu May 22, 2025 6:31 pm
donny5 wrote: Thu May 22, 2025 3:22 pm I've been looking into getting some small Pseudotrophy cichlids for my 48-gallon tank. They max out at 3 inches, so I think it's doable. I've done a lot of research and I know I'll need to overfilter the tank. Would two large HOB filters work for this, or is there a better setup you'd recommend? I'm thinking of keeping 2 males and 5 or 6 females, with a bunch of hiding spots for them.

I know I can overstock the tank a bit, up to around 18 fish based on the 80% rule, then cut that in half. But I'm wondering if 8 mbunas would be too few for a tank this size?

My main concern is that I want to be able to do weekly water changes. If I have to do them every 3 days, it's just not gonna work for me, especially if I go on vacation. So I need a setup that can handle that.
I've got a 48x18x18 tank with 7 cichlids, all about 3" long. Tydal 75 HOB filter does the job. The cichlids love digging and stirring up the sand substrate, and the HOB picks up all the detritus - no need to vacuum.

Don't get why overfiltering is a thing - doesn't reduce nitrate levels. Live plants are the way to go, though. I've got large rocks around the base of the plants, and the cichlids leave them alone.

Weekly or 10-day water changes work for me - around 30% each time. If I'm away, it might be 3 weeks before I change the water again. But changing water every 3 days? No thanks, I'll find another hobby.

Can't help with the number of fish, though.
Thanks for the input, really appreciate it. I've got a slightly smaller tank, 36x18x18, but I've decided to go with two Tidal 110s - probably overkill, but I can always dial back the flow. My plan is to use one for sponges and bio media, and the other for filter floss and Purigen. I've also got a bunch of hornwort floating at the top, which I've had good luck with in my planted tanks. Plus, I'll have some philodendrons planted around the edges - think that'll help with water quality. With all this in place, I'm hoping I can get away with weekly water changes and a total of 10 fish that'll max out at 3.5 inches.

Do you keep any Chindongos? Specifically, the Pseudotropheus saulosi? Hopefully I got the spelling right.
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Tigger
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Re: Filtration advice for a 48-gallon tank

Post by Tigger »

I think you're pushing it with 10 saulosi in a 36" tank, even with your filtration setup and water change plan. Keep a close eye on those nitrate levels, if they're above 20ppm, you'll need to adjust your water change schedule. I've had good luck with Electric Yellow, Acei, and Peacock, but I've found that longer tanks are better suited for keeping multiple males, especially with species like saulosi.
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donny5
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Re: Filtration advice for a 48-gallon tank

Post by donny5 »

Tigger wrote: Thu May 22, 2025 6:31 pm
donny5 wrote: Thu May 22, 2025 3:22 pm I've been looking into getting some small Pseudotrophy cichlids for my 48-gallon tank. They max out at 3 inches, so I think it's doable. I've done a lot of research and I know I'll need to overfilter the tank. Would two large HOB filters work for this, or is there a better setup you'd recommend? I'm thinking of keeping 2 males and 5 or 6 females, with a bunch of hiding spots for them.

I know I can overstock the tank a bit, up to around 18 fish based on the 80% rule, then cut that in half. But I'm wondering if 8 mbunas would be too few for a tank this size?

My main concern is that I want to be able to do weekly water changes. If I have to do them every 3 days, it's just not gonna work for me, especially if I go on vacation. So I need a setup that can handle that.
I've got a 48x18x18 tank with 7 cichlids, all about 3" long. Tydal 75 HOB filter does the job. The cichlids love digging and stirring up the sand substrate, and the HOB picks up all the detritus - no need to vacuum.

Don't get why overfiltering is a thing - doesn't reduce nitrate levels. Live plants are the way to go, though. I've got large rocks around the base of the plants, and the cichlids leave them alone.

Weekly or 10-day water changes work for me - around 30% each time. If I'm away, it might be 3 weeks before I change the water again. But changing water every 3 days? No thanks, I'll find another hobby.

Can't help with the number of fish, though.
I'm thinking 1 male and 4 females would be a good number for my 36" tank. I'm trying to minimize aggression, so I want to keep the male to female ratio in check. I've read that too many males can cause problems, so I'm leaning towards just one. Do you think that's a good idea?
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Tigger
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Re: Filtration advice for a 48-gallon tank

Post by Tigger »

donny5 wrote: Thu May 22, 2025 3:22 pm I've been looking into getting some small Pseudotrophy cichlids for my 48-gallon tank. They max out at 3 inches, so I think it's doable. I've done a lot of research and I know I'll need to overfilter the tank. Would two large HOB filters work for this, or is there a better setup you'd recommend? I'm thinking of keeping 2 males and 5 or 6 females, with a bunch of hiding spots for them.

I know I can overstock the tank a bit, up to around 18 fish based on the 80% rule, then cut that in half. But I'm wondering if 8 mbunas would be too few for a tank this size?

My main concern is that I want to be able to do weekly water changes. If I have to do them every 3 days, it's just not gonna work for me, especially if I go on vacation. So I need a setup that can handle that.
I don't keep Pseudotropheus saulosi, but 1 male and 4 females seems like a good balance to me. Having two males would require more space, as each male needs its own territory to call home.

I've seen some people keep male-only Malawi tanks, overstocking to spread the aggression. However, this doesn't necessarily reduce the aggression - it just means no single fish is the sole target. The weakest fish will still get picked on, unfortunately. I prefer not to overstock, as it makes it tough to keep nitrate levels in check.
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donny5
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Joined: Mon Nov 04, 2024 4:58 am

Re: Filtration advice for a 48-gallon tank

Post by donny5 »

Tigger wrote: Thu May 22, 2025 6:31 pm
donny5 wrote: Thu May 22, 2025 3:22 pm I've been looking into getting some small Pseudotrophy cichlids for my 48-gallon tank. They max out at 3 inches, so I think it's doable. I've done a lot of research and I know I'll need to overfilter the tank. Would two large HOB filters work for this, or is there a better setup you'd recommend? I'm thinking of keeping 2 males and 5 or 6 females, with a bunch of hiding spots for them.

I know I can overstock the tank a bit, up to around 18 fish based on the 80% rule, then cut that in half. But I'm wondering if 8 mbunas would be too few for a tank this size?

My main concern is that I want to be able to do weekly water changes. If I have to do them every 3 days, it's just not gonna work for me, especially if I go on vacation. So I need a setup that can handle that.
I've got a 48x18x18 tank with 7 cichlids, all about 3" long. Tydal 75 HOB filter does the job. The cichlids love digging and stirring up the sand substrate, and the HOB picks up all the detritus - no need to vacuum.

Don't get why overfiltering is a thing - doesn't reduce nitrate levels. Live plants are the way to go, though. I've got large rocks around the base of the plants, and the cichlids leave them alone.

Weekly or 10-day water changes work for me - around 30% each time. If I'm away, it might be 3 weeks before I change the water again. But changing water every 3 days? No thanks, I'll find another hobby.

Can't help with the number of fish, though.
Sounds like a plan. 4 ladies to keep the king happy, and we should have a peaceful kingdom.
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