Is there any real reason an XP2 couldnt run a 55

[Toby_H]

remember, with canisters, 4x turnover is fine because of all the media capacity.
　
its only with HOB's you need 10x because they hold so little media in comparison..

　
I wholey and truly disagree with this common belief...
　
The AC110 holds 4 liters of media... the XP2 holds less than 2 liters... So the media volume theory is simply not true…
　
As for circulation, it doesn’t matter where the circulation is coming from, dead spots result when there isn’t enough current… And with dense décor, the approximately 175 gph the XP2 offers, can allow dead spots…
　
I truly feel the above quote is drastically over simplifying a concept that allows people to misunderstand what the truth really is…
　
Just like the “1 inch of fish per Gallon” is a real concept based on facts… but presented in such a general way that it is not true…

 

[12 Volt Man]

The AC110 holds 4 liters of media... the XP2 holds less than 2 liters... So the media volume theory is simply not true…

something is wrong here. I can put a whole AC110 sponge (cut up to fit) in one basket of an XP. that means I can put two full sponges in an XP2.

two full 110 sponges will not fit in an AC110. you can use one but you need to cut some of the second one off to fit..

??

I think your right though, the XP2 doesn't hold twice as much media than the AC110, but it does hold 'more'

how much more is hard to say..

 

[12 Volt Man]

ps using the powerjet nozzle supplied with the XP's will result in better circulation than using the spray bar..I love the powerjets its sort of like having a powerhead output on the output of the canister..

 

[bullwinkle]

The XP2 only runs at about 175gph actual flow. with the 1.75 liters of media one basket can hold the bio will not be an issue. The flow is not enough IMO to effectively filter a 55g mechanically speaking.

I base my opinion off of a 55g bare bottom that was filtered by a xp3(185gph actual flow). I set up the output in a couple different ways to direct flow across the bottom of the tank, but could not get enough flow to move the debris all the way across the tank.

How does one determine the "actual flow" of a filter? Is there a formula or are you estimating and if so what are you basing it on? Also why do these filters have a much lower gph than they claim in advertising/on the box??

 

[12 Volt Man]

actually, the 175g is the number from the box I believe.

because Rena actually publishes the flow rate and then the flow rate with media seperately on the box.

no one else does this.

I believe thats part of why some feel rena has a lower flow rate when in fact they do not.

its because some people will compare the listed flow rate with media of the rena and compare it to a competitor's flow rate without media, which is actually comparing apples to oranges...

 

[Toby_H]

something is wrong here. I can put a whole AC110 sponge (cut up to fit) in one basket of an XP. that means I can put two full sponges in an XP2.

The media chamber of an AC 110 measures 10" x 4" x 7.5"... that is 300 cubic inches... which is just under 1 1/4 gallons... which is a over 4.5 liters...

Thus, the AC 110 has double the media volume of the XP2...


Yet that proven fact aside...


A 55 gallon tank densely decorated can have easily allow dead spots with only 175 gallons of water movement...

 

[Deaths Sting]

i would use 2 Xp2s if it was my tank. i have 2 AC110s on my 56 gallon. i couldn't be happier with them.

maybe add an AC to it! doesn't have to be the 110, but i would use that one...)

also having 2 filters is a big plus, God forbid one fails. you can also rotate filter maintenance between the 2.

 

[12 Volt Man]

The media chamber of an AC 110 measures 10" x 4" x 7.5"... that is 300 cubic inches... which is just under 1 1/4 gallons... which is a over 4.5 liters...

Thus, the AC 110 has double the media volume of the XP2...


Yet that proven fact aside...

its not a proven fact.

here is why: there is a difference between the total media capacity and the useable media capacity.

with the rena baskets the full volume is usable as water flows through all of it.

with the AC's not all of that space can be used for media.

you can stack two AC 110 sponges on top of one another in an AC110 basket, put it in your filter, and the water will only be flowing through the first 2/3d's of the media. the top portion of the upper level sponge will be in dry air. which is useless.

I just tried it


hence why I can fit more media inside my Renas than I can in my AC's...

not all the media space in the AC 110 media chamber is usable. sure its there, but your water won't be flowing through it..

with a canister, it all gets used..

thats the difference

this is probably why I can fit more media in an XP3 than an AC110. sure, you can fill up your AC basket right up to the thumb handles, but its not all going to be in contact with the tank water, which of course is the key..with a canister you can put all the media that you did in the AC but it all gets used to filter. none of it is left dry.

that difference is crucial.

 

[Toby_H]

12 Volt... I do not mean to be argumentative... but take a closer look, you are wrong...



The dry sponge is 9.5", but in use it is 10"... In use, there is a 10" span between the side walls of the 'media basket'...

At the top of the 'media chamber', the inside width (front to back) at the water surface is 4"... tapering down to 3.75" at the bottom... giving a 3.875" average

When in use, the water depth is 7 3/8". The media is held up 3/4" by the 'basket'... giving the potential of submerged media of 6.625" deep


This gives a God's honest internal dimentions of the submerged media chamber 10" x 3.875" (averaged) x 6.625 = 256.7 cubic inches... Which is 1.11 US Gallons... which is 4.2 liters...


So literally, the AC 110 (4.2 liters) has a submerged media capactiy 2.4 times greater than the XP2 (1.75 liters)...

You originally took the position that the XP2 holds more... not only does it hold less... it holds less than half...

So not only was your initial evaluation wrong, it was extremely wrong...

So even with arguments that a small portion of this submerged media chamber may not have maxiumum flow... no matter how you look at it, the AC has more usable media space than the XP2 (by a long shot)...



And that proven fact aside...

A 55 gallon tank densely decorated can have easily allow dead spots with only 175 gallons of water movement...

 

[12 Volt Man]

I understand that we are not arguing. this is a discussion.

what I am saying is that there is a difference between what the numbers say on paper and the real world application.

for example, in my XP3, I have for media:

1 AC110 sponge cut up in the bottom basket (fills it)
4 of the rena pads in the second basket (fills it)
a whole bunch of the rena bio rings and a rena carbon bag on top of all that.

I cannot fit all of this into an AC110. its an impossibility. no matter what the numbers say I should be able to. the reason is that the math does not account for the media that gets unused even though it occupies the space in the filter.

now, I realize that I am using an XP3 as an example, because this is what I have.

but the XP2 is the same its just that the top basket is missing. so that means I could put either:

1 AC110 sponge and 4 rena pads

or

1 AC110 sponge and fill the top basket with biomaterial (or a bit less and add a carbon bag)

both of these are about equivelent to what you could fit into an AC110 filter and have all the media submerged.

so, in the real world application, it looks to me like the AC110 would hold about the same amount of media as an XP2 would. not twice as much..

I stand corrected as I had originally said the XP2 would hold a lot more. now, after doing the test with the extra AC110 sponge in my AC, it doesn't..

interesting..