advice needed for 390 gallon canister setup

[sneakhedkeepa]

Hi fellow friends MFK.

newbie here first time owner of large tank and prefer canisters over sump.
Tank setup for 2 snakeheads.
7ft x 3 x 2.5 that is approximately 393 gallons or 1500 liters. Will 2 eheim xl canisters be enough for beneficial bacteria growth and full cycle ? One canister on each side. 3500 l/hr on each side.
Is it ok if I don’t fill tank water to the top but maybe 3 quarters or a little more so is less then 1500 liters.
2 canisters and 3500 l/hr on each side, is it enough for good beneficial bacteria growth and a full cycle for a healthy tank ?

 

[Toby_H]

I've never had a tank that didn't have enough "Bio Media" / Surface Area to host the necessary amount of bacteria. So while I am not discouraging the use of bio media, I wouldn't worry about having enough. You'll have enough no matter what.

That said... You will need enough filtration to provide water movement throughout your tank... and you will want your filtration to do a certain amount of mechanical filtration for you. "How much" mechanical filtration you want your filters to do is up to you, remembering that whatever they do not do, you'll have to.

With a tank that size (impressive tank by the way), it's less about quantity and more about placement. With that in mind, decor means a lot. As if you have a lot of obstacles breaking the water flow across the bottom of the tank, you may want to add a few intermediate powerheads to help move waste. If its wide open space, you may want both intakes at one end, both returns at the other, creating a rolling flow across the bottom from one end to the other.

Consider the details, but in short, I'd expect the two Eheim canisters to be "enough", though you'll want to compensate with some additional water movement (powerheads or the like) to move physical waste.

 

[Rocksor]

You could use all eheim coarse sponges as your bio-media and it would be enough to keep your tank cycled. As long as ammonia=nitrites= 0ppm everyday, then you have enough media and filtration. I used 1 fine sponge filter rated for a 40g tank (ATI Sponge III), and it kept my quarantine tank with 12.5" long fish safe from ammonia and nitrites.

 

[sneakhedkeepa]

I've never had a tank that didn't have enough "Bio Media" / Surface Area to host the necessary amount of bacteria. So while I am not discouraging the use of bio media, I wouldn't worry about having enough. You'll have enough no matter what.

That said... You will need enough filtration to provide water movement throughout your tank... and you will want your filtration to do a certain amount of mechanical filtration for you. "How much" mechanical filtration you want your filters to do is up to you, remembering that whatever they do not do, you'll have to.

With a tank that size (impressive tank by the way), it's less about quantity and more about placement. With that in mind, decor means a lot. As if you have a lot of obstacles breaking the water flow across the bottom of the tank, you may want to add a few intermediate powerheads to help move waste. If its wide open space, you may want both intakes at one end, both returns at the other, creating a rolling flow across the bottom from one end to the other.

Consider the details, but in short, I'd expect the two Eheim canisters to be "enough", though you'll want to compensate with some additional water movement (powerheads or the like) to move physical waste.

large corner piece tree stump driftwood, some small stone and pebbles. sorry I forgot to mention the canisters are loaded with biohomme plus but about the decor water movement and placement.. man that really got me lost.. i have 1 canister on each side like this at the moment.. should I place the two in takes together on one side and both returns together on other side ? i can make the return facing down instead will help ? Man I really hate to put a wave maker in for bottom water movement.. will Air stone help lol..

 

[Rocksor]

You don't need a wavemaker for bottom movement. The suction of the XL canisters is enough to circulate the water in the bottom. Leave the intakes to the canister where they are. I would put coarse sponges on those intakes to prevent sand/gravel going in, maybe the eheim pre-filter would fit the intakes.

You could place the output on the side panel about 1/2" below the water line and point it up at about 45 degree angle to agitate the surface. Basically both outputs would be facing each other. Or you could put one on the side panel (on the left) blowing to the right, and the remove the spray bar on the other with only an elbow connector (blowing to right). The elbow would be halfway in the water.

 

[sneakhedkeepa]

You could use all eheim coarse sponges as your bio-media and it would be enough to keep your tank cycled. As long as ammonia=nitrites= 0ppm everyday, then you have enough media and filtration. I used 1 fine sponge filter rated for a 40g tank (ATI Sponge III), and it kept my quarantine tank with 12.5" long fish safe from ammonia and nitrites.

I have black and white sponges along with bio media in the canister. I’ve yet to test my water, not very confident with my setup at the moment. I’ve thrown fish poop in and I’m guessing it take about few hours for it to get sucked into the canister. Hmm is that good or bad. I will monitor further.

 

[Rocksor]

I have black and white sponges along with bio media in the canister. I’ve yet to test my water, not very confident with my setup at the moment. I’ve thrown fish poop in and I’m guessing it take about few hours for it to get sucked into the canister. Hmm is that good or bad. I will monitor further.

Personally I don't like fish poop getting into canisters. It just means I have to open up the canister sooner than if I put a coarse sponge as a pre-filter. I clean the pre-filter in old tank water with each water change. It catches a lot of waste,

 

[sneakhedkeepa]

You don't need a wavemaker for bottom movement. The suction of the XL canisters is enough to circulate the water in the bottom. Leave the intakes to the canister where they are. I would put coarse sponges on those intakes to prevent sand/gravel going in, maybe the eheim pre-filter would fit the intakes.

You could place the output on the side panel about 1/2" below the water line and point it up at about 45 degree angle to agitate the surface. Basically both outputs would be facing each other. Or you could put one on the side panel (on the left) blowing to the right, and the remove the spray bar on the other with only an elbow connector (blowing to right). The elbow would be halfway in the water.

ok. so I leave it as it is. Remove spray bar, but keep the elbows with both output facing each other for water movement. Noted, but the output on the right is kind of affected because of the driftwood though, also is ok for intake to be placed behind the driftwood ?

 

[Rocksor]

ok. so I leave it as it is. Remove spray bar, but keep the elbows with both output facing each other for water movement. Noted, but the output on the right is kind of affected because of the driftwood though, also is ok for intake to be placed behind the driftwood ?

If you have the outputs on the side panels, you can keep the spray bar if you want, up to you. As long as you have rippling on the water surface.

One of my intake is behind driftwood like yours, and it's not an issue. When I dosed with those liquid peat, I put it in the area of the intakes (and by the driftwodd that I had), and I could clearly see how the intake to the flow went. This is for Eheim G160/Eheim 2217 on a 24" wide tank, which aren't as powerful as your filters.

 

[FJB]

I too agree that with those 2 filters (particularly with prefilters added) and regular (generous) water changes, it should be fine. Adding powerheads would be nice but not strictly necessary. Of course you have not spoken about stocking, nor about your planned maintenance routine.
Out of curiosity - why don't you want the water level any higher? Are you planning on a turtle or something like that? Or are you thinking of something like a vivarium? Although you are lucky to have such a huge tank, it seems that the volume may become more like a 280gal at that level, which is very respectable but much less than it could be. Of course this is coming from someone whose largest tank is a measly 125gal! Good lucke!