A few things:
About CO2 and filter choice... it's fish or plants. Increasing CO2 decreases O2. Yes, for a planted tank I'd use a cannister with a return point BELOW the surface. For me, I don't get enough satisfaction from keeping a planted tank to justify the work involved. It's also extremely difficult to have a "clean" plant tank. Every plant is an obstacle to water flow and a pocket for debris build-up.
Most HOB filters are designed by the manufacturers NOT for efficiency or functionality but to sell cartridges. They make much more from cartridge sales than filter sales.
The biggest plus for a wet/dry sump arrangement hasn't been mentioned... it's the higher oxygen level. The aeration occurs within the sump and isn't dependent on the return method, allowing for more flexibility in design. The other designs require surface agitation for oxygen transfer.
As for the 10X rule... I'm a believer. Comparing an Emperor 280 to a 400 for example, the cost are similar. The 400 isn't much more expensive than the 280, uses 2 cartridges and 2 bio-wheels vs 1 each on the 280. Too much flow? Just adjust it down some. As the filter ages you change the normal setting to a higher level. If you bought the smaller unit initially you'd have to buy an additional filter. Also, the higher flow rate allows you to crowd the tank successfully, more than you could otherwise. Yet another reason, the bigger the fish the larger the anal opening. Larger feces requires more water movement to break it up or remove it.
Hagen's line, which I feel is the best of the HOB choices, uses a sponge and carbon bag media vs cartridges. Yes, you could also use cartridges, Hagen's into making money too. Another reason for Hagen's line being my first choice, the water level can fluctuate and within reason, it won't effect the filtration. Unlike Marineland's filter line, the water level doesn't have to be near the top of the tank, making Hagen's line suitable even for a turtle tank.
About cannisters... it depends completely on the unit you've chosen. I feel Eheim is superior to others generally but find some units within the product line poor choices. The Eheim family is no longer the decision maker for the company. Market share has overshadowed integrity. The tiered pricing structure has disappeared, making it a poor business decision to stock many of their products in a store environment. Eheim's, from the bottom, through the media and out, flow, is proven to provide the cleanest water when packed properly compared to other cannisters. If you disbelieve this, just ask another manufacturer. Better filtration is NEVER the reason they state to sell you on their design vs Eheim.
About CO2 and filter choice... it's fish or plants. Increasing CO2 decreases O2. Yes, for a planted tank I'd use a cannister with a return point BELOW the surface. For me, I don't get enough satisfaction from keeping a planted tank to justify the work involved. It's also extremely difficult to have a "clean" plant tank. Every plant is an obstacle to water flow and a pocket for debris build-up.
Most HOB filters are designed by the manufacturers NOT for efficiency or functionality but to sell cartridges. They make much more from cartridge sales than filter sales.
The biggest plus for a wet/dry sump arrangement hasn't been mentioned... it's the higher oxygen level. The aeration occurs within the sump and isn't dependent on the return method, allowing for more flexibility in design. The other designs require surface agitation for oxygen transfer.
As for the 10X rule... I'm a believer. Comparing an Emperor 280 to a 400 for example, the cost are similar. The 400 isn't much more expensive than the 280, uses 2 cartridges and 2 bio-wheels vs 1 each on the 280. Too much flow? Just adjust it down some. As the filter ages you change the normal setting to a higher level. If you bought the smaller unit initially you'd have to buy an additional filter. Also, the higher flow rate allows you to crowd the tank successfully, more than you could otherwise. Yet another reason, the bigger the fish the larger the anal opening. Larger feces requires more water movement to break it up or remove it.
Hagen's line, which I feel is the best of the HOB choices, uses a sponge and carbon bag media vs cartridges. Yes, you could also use cartridges, Hagen's into making money too. Another reason for Hagen's line being my first choice, the water level can fluctuate and within reason, it won't effect the filtration. Unlike Marineland's filter line, the water level doesn't have to be near the top of the tank, making Hagen's line suitable even for a turtle tank.
About cannisters... it depends completely on the unit you've chosen. I feel Eheim is superior to others generally but find some units within the product line poor choices. The Eheim family is no longer the decision maker for the company. Market share has overshadowed integrity. The tiered pricing structure has disappeared, making it a poor business decision to stock many of their products in a store environment. Eheim's, from the bottom, through the media and out, flow, is proven to provide the cleanest water when packed properly compared to other cannisters. If you disbelieve this, just ask another manufacturer. Better filtration is NEVER the reason they state to sell you on their design vs Eheim.
