Red tail shark is chasing tetras - Page 2

[GlennO]

What do you mean “halve the manufacturer's stated flow rate for the filters.”? And would I get 2 of those filters since I want 2 filters or should I half the 220 to 330gph and get to with half of the gph?

I find that, in practice, canister filters when hooked up and full of media usually produce about 60%-70% of the output stated by the manufacturer. So it's just a matter of taking that into account when calculating the total output of your filters to achieve 4 to 6 times turnover of tank volume per hour.

However, I don't use HOB's and don't know if the same applies to them. Since you're considering them it's probably best for someone else to comment on the model you're looking at.

Might be best to start a separate thread on filter selection since it is off topic.

 

[Mcasella]

If I got this would I still need 2 filters.

I find this brand to be a lower quality filter that could break fairly easily without warning.

Yes, for HOB (hang on back) filters you want 8-10 times the volume of the tank for turnover (320-400 gallons per hour for a 40 gallon tank is what you are looking at). So two filter is going to make it easier. Generally being full of media (whether it be carbon, filter matting, or some other media) drops the flow rate of filters, regardless of if they are canister or HOB. Something rated for a 120 or slightly larger for a hob would be enough for a single filter on a 40, however two smaller filter is easier to get and easier to keep from losing your bacteria.

 

[Fishowner24]

So for a 55 gallon what size of filter would I need if I got 2?

 

[Fishowner24]

And 320-400 gallons per hour is that what I would get for 2 filters for a 40 gallon tank or would I get that for 1 filter for a 40 gallon tank?

 

[Mcasella]

So for a 55 gallon what size of filter would I need if I got 2?

550 gph for 10 times volume.

And 320-400 gallons per hour is that what I would get for 2 filters for a 40 gallon tank or would I get that for 1 filter for a 40 gallon tank?

Either. Both options would work.