Internal Sump with Chiller?

CaptainKiwi · 2026-10-18T13:41:46-0400

This is for a freshwater palduarium for some semi aquatic lizards, but I am using spare marine equipment and ultimately it's still water

. I'm also fairly confident I will get a much better answer here than I will on reptile and freshwater forums cause y'all are awesome!

I am planning a water section in a tank of dimensions 120cm long x 50cm wide x 18cm tall - approximately 100L. I need to attach a chiller to this and want to do it without a sump ideally as I Id like to put another tank below it and therefore need as much space in the cabinet as possible. I also need the flow out from the filter to be very very low as they get very stressed in medium/high flows.

I was thinking about doing an internal sump AIO style along the back as this would be more than enough filtration, but could I add a chamber that has an in and out to a chiller beneath? I have a Neptune COR 15 so I can have the high flow required as I have an Aqua medic Titan 1500. I was thinking about using some of the flow to pump water up to a drip wall at the top of the tank (it would be 1.8m from the pump to the top so that would take a lot of the flow), but would that much flow through a small compartment in a low flow system be crazy and loud?

davidm777 · 2026-10-18T14:42:49-0400

LOL. The pump is for 5,700 litters per hour and you trying to run a chiller for 1,500 liters on a body of water of 100 liters. Slightly overkill on my opinion.

What temperature is the room in summer and what temperature you trying to achieve?

davidm777 · 2026-10-18T14:50:03-0400

I don't think it's a good idea. To run that chiller you will need a good amount of waterflow, otherwise you run the problem of either freezing the water at the evaporator or running the evaporator so cold that you might flow liquid refrigerant back to the compressor. If you might find a setting that kind of works, doe the size of the chiller you might end up short cycling the chiller... just doesn't seem like a good idea IMO.

PapaFishRocks · 2026-10-18T15:23:21-0400

Do you really need a chiller?

What temps do the lizards need?

I have a Vampire Crab paludarium, with cherry shrimp. Sponge filter and no heater. Water temps vary from 72-75

CaptainKiwi · 2026-10-18T15:28:04-0400

davidm777 said:
LOL. The pump is for 5,700 litters per hour and you trying to run a chiller for 1,500 liters on a body of water of 100 liters. Slightly overkill on my opinion.
What temperature is the room in summer and what temperature you trying to achieve?

I will be honest, if I have to buy new parts to do it, I will, but this is what I have at the moment so I'm trying to make it work

davidm777 said:
I don't think it's a good idea. To run that chiller you will need a good amount of waterflow, otherwise you run the problem of either freezing the water at the evaporator or running the evaporator so cold that you might flow liquid refrigerant back to the compressor. If you might find a setting that kind of works, doe the size of the chiller you might end up short cycling the chiller... just doesn't seem like a good idea IMO.

Yeah, I think this setup could work for a 100L sump, not a 100L tank lol. Could it work using a smaller pump and chiller?

CaptainKiwi · 2026-10-18T15:32:53-0400

PapaFishRocks said:
Do you really need a chiller?

What temps do the lizards need?

I have a Vampire Crab paludarium, with cherry shrimp. Sponge filter and no heater. Water temps vary from 72-75

I have Chinese crocodile lizards, my water can get to 28 degrees during the summer in my room, and that is too hot. Also during the winter I'd like it to get down to 7-8 degrees, so it will be running during peak summer and peak winter!

davidm777 · 2026-10-18T16:14:21-0400

What about investing on a mini split instead? It will help out with the lizards and you'll get to enjoy it also. If it's a small apartment they also have the portable ACs. Is just an idea.

PapaFishRocks · 2026-10-18T17:12:22-0400

CaptainKiwi said:
I have Chinese crocodile lizards, my water can get to 28 degrees during the summer in my room, and that is too hot. Also during the winter I'd like it to get down to 7-8 degrees, so it will be running during peak summer and peak winte

Those are cool lizards. Post pics of your setup, when it’s done. I love paludariums.

CaptainKiwi · 2026-10-18T17:30:26-0400

davidm777 said:
What about investing on a mini split instead? It will help out with the lizards and you'll get to enjoy it also. If it's a small apartment they also have the portable ACs. Is just an idea.

I have AC, but I can't run it when I'm not at home so it has to be a chiller. Plus making my projects more intricate than necessary is my favourite thing to do!