how much gph flow filter do i need for a 125 gallon? is a rena xp4 good enough?

  • We are currently upgrading MFK. thanks! -neo
Behold the power of the all knowing google!

FilStar xP3 Up to 175 Gallons 350 GPH 9-1/2" x 8-1/2" x 17" 19W
FilStar xP4 Up to 260 Gallons 450 GPH 13" x 9" x 17" 31W

Rena rates the xP4 filter at over twice the size (gallons) of your tank. Thats way more filter than you need. Save some money and get an xP3, unless you know you're going to upgrade tank size soon.

Someone posting after me will say "hang an AC110 on the back".
 
kallmond;3644283; said:
Someone posting after me will say "hang an AC110 on the back".


Bwhahaha! Good one! :) :ROFL::ROFL::ROFL:









...Seriously though... Hang an AC110 on the back!
 
Poklei;3644230; said:


All depends on what your stocking is?

If you keeping rays, or very messy fish, i would recommend GPH rate of at least 6 x the tank volume (some recommend X 10)

If stocks are low and only 1 or 2 fish, the XP4 will be fine.

Its always good to have more filtration than what is specified. That ways, you can add more fish later.

I dont like my filters being overworked :D ( i use 2 x fx5 on a 125g)
 
It all depends on what you want out of your filtration system.

The XP4 only flows 190gph once loaded with media. And IMO would make a nice filter for a 55g tank and no more.

I design my filtration systems so that there is little to know debris ever found in the tank. My goals for my tanks are maintenance oriented. With turn over rates of around 15x there is allmost never a need to vacumm the tank bottom. A water change is just a drain and refill.

A turn over rate as small as 2-3x an hour will be enough to handle a decent bio load. But will do allmost nothing for debris removeal from what I have seen.

So if your filtration goals are only to be a bio-filter and not a mechanical means of debris removal. Then the xp4 and a HOB will be fine.

If you want to lower the tanks maintenance considerably then get enough filtration going to get your turn over rate up over 10x.

The cheapest and best way of doing so would be a DIY sump. I built my last sump for my 125 for $120 using some thing I had laying around. That was a used overflow $40, and DIY sump $20 and a new quiteone 5000HH $60.
 
At what point do you worry about your fish feeling like they're swimming against a vortex?
I'd hate to be a fish in your tank swimming in this:
1071p3cmaelstron_907pfinal.jpg


So you don't have to use a gravel vac when you do water changes.
 
lol its a matter of preference my good friend.... usually 2 filters work better than 1 giant one.. however thats just my preference...
 
My first suggestion on selecting a filter is to completely ignore the "up to XXX gal tank" rating they offer. This is misleading nonsense...

You will hear suggestions of pushing your tanks full volume through the filter anywhere from 3~10 times per hour with plenty of people who use even higher turnover rates. The more flow your tank has the less waste/debris will settle on the bottom.


Do note that "3 times turnover" is considered very little... and the XP4 will give your 125 gal aroudn half of that...
 
I myself would neve have a turnover of any less than 4x / hr on any tank. The last "monster" tank I had was 110g and had a circulation rate of 1100g /hr.
2 AQ 110's
2 power heads connected to a under gravel filter( can't remember what the pwr heads were) I just remember the rediculous /hr rate! Lol Needless to say the tank was always crystal clear.
 
I've used an actual flow rate of 22.5 times per hour on a 125 gal tank... while I agree this was unnecessary, the fish had no problems swimming in it...

I used AC 110s (500 gph) to filter 29 gal tanks (rated 17x) when breeding Apistos (Dwarf Cichlids) and their fry (reeeeaaaallllyy small) had no problems navigating.


Just reviewing rough numbers in my head... I would estimate a toilet flushing to be around 1,000~1,800 times turnover...



kallmond;3644558; said:
At what point do you worry about your fish feeling like they're swimming against a vortex?
I'd hate to be a fish in your tank swimming in this:
1071p3cmaelstron_907pfinal.jpg


So you don't have to use a gravel vac when you do water changes.
 
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