Why Are Pumps Rated For Tanks Not Able To Do What They Say?

[stuhyde]

For example, a Tetratec EX1200, advertised by Tetratec to be able to filter tanks up to a recommended 500L.

Ive been told by a few people that its not enough filtration for a 330L tank even though its well under the recommended maximum size tank.

I would have thought this would over filter it. I understand that you could run 5 of these on a 330L tank and it would be "better", but surely 1 is sufficient for this application?

Discuss.

 

[AdAndrews]

the higher than can say, the more people will buy, coz then the people with size tanks 330l+ obviously will think ok i will have that... its all a money game.

if they said its only for 330l less people would fit into that bracket and many people would then say.. suitable for 200l+

 

[BigC]

You loose output because of the head height The pump will probably be having to pump to around 3' depending on your stand height. Whilst having to do this extra work it will loose a bit of umph. so to speak
Regards
BigC

 

[Davo86]

In an Ideal World you are wanting to circulate water around the tank a number of time per hour,

This will vary depending on what you keep but the smallest amount of turnover you want to aim for is 4x per hour, (ideally 5)

Therefore in a 330L tank you are really needing a filter that will do at the very least 1320 Litres per hour.

Unfortunately most manufacturers test their products without media and therefore don't give you a very clear picture of what the filter is actually capable of doing, whilst a Tetratec EX1200 runs at 1200lph when empty, once it is full of media this is reduced by a far amount, and although its hard to put a figure on what the turnover actually is when full, I'd estimate that it is actually between 600-800lph

I have previously had a Tetratec EX1200 running on a well stocked 240L tank and tbh you could tell that it was noticeably struggling

 

[stuhyde]

Interesting replies, thanks for the input!

Davo86 - How could you tell it was struggling? Was this through the water parameters?

 

[aaronnorth]

when it says for 500l tanks that means there should be sufficient surface area for bacteria to colonize, this is ok so long as you stock sensibly for a 500l tank.
It is the flow rate that is affected, so there may not be enough flow in the tank.

So yes, a TT1200 can filter a 500l tank (biologically & mechanically), but you may need to add a powerhead to make up for the loss in flow.

 

[stuhyde]

when it says for 500l tanks that means there should be sufficient surface area for bacteria to colonize, this is ok so long as you stock sensibly for a 500l tank.
It is the flow rate that is affected, so there may not be enough flow in the tank.

So yes, a TT1200 can filter a 500l tank (biologically & mechanically), but you may need to add a powerhead to make up for the loss in flow.

So what about said filter in a lesser 330L tank thats not fully stocked?

 

[CKutz]

i've been trying to think of a way to figure out what your filters actual rate is, if you reallyyyy want to figure it out.

i have a HOB filter, i was thinking you could use a bucket, fill it with some amount of water, not necessary to know. then run it to get the water flowing at the regular rate, the water going back into the bucket..now get another bucket, smaller maybe, and put the opening of filter over the edge of its bucket so the water comes out into another bucket. use a stopwatch to time the filter running for 15 seconds. stop the filter. now use a measuring cup or something to figure out how much water went into the 2nd bucket (X amount). provided you get your amount of water in liters you could figure out the liters per hour by:

X L / 15 seconds * 60 seconds * 60 minutes = amount of water in liters per hour.

i'm sure if you really want to you could do this with other systems, you'd just have to mock how it was set up with your tank so the flow is the same....i think it would work...just in case anyone really wants to know haha.