Filter Water Return Problem - Any Advice?

[sonicfish73]

I've been trying to work out the turn-over rate if a filter sat below my tank. I've just ran a test using my internal filter to see how it performed returning the water from a bucket 110cm below tank level. I put 9 litres of tank water in the bucket and timed the filter pumping the water up a hose pipe into a bowl until it reached 1 litre. Dunno if I done this right but here's how I worked it out.

It took 19 seconds to shift 1 litre.
I then divided 1000 mls by 19 seconds.
This gave 52.5 mls per second.
Multiply that by 60 seconds = 3150 mls per minute.
Multiply again by 60 = 189000 mls per hour (189 litres).

Then i divided the 189 litres per hour by the actual volume of water in my tank without substrate etc.
This gave a result which indicated it would only turn the water over once an hour. Surely I have mis-calculted something?!!

I'm think I've worked it out correctly. I'm assuming (and hoping) that most external filters run better from below the tank than the one I just used or will I have to go for something at least twice as powerful as my internal?

Anyone got a 55 gal tank with external filtration? How many litres per hour should I really be going for as my tank has a lot of fish? I'm confused by this.

 

[rabbut]

Good news or medioca news first? Good news, OK then

My maths agrees with yours

Medioca news is that whether or not that's enough depends on what fish you plan to keep...

What filter do you have and what are your stocking plans? 1 times an hour turn-over is too low for almost all set-up's, but there are some situations where you'd *get away* with that little flow

All the best
Rabbut

 

[sonicfish73]

Good news or medioca news first? Good news, OK then

My maths agrees with yours

Medioca news is that whether or not that's enough depends on what fish you plan to keep...

What filter do you have and what are your stocking plans? 1 times an hour turn-over is too low for almost all set-up's, but there are some situations where you'd *get away* with that little flow

All the best
Rabbut

No sorry for not making it clear, the 1000L/H filter is already in place in my 55 gallon freshwater with tetras, rams, corys. I'm looking to replace it for an external filter which will give a similar output but then realised that filling it with the media and placing it 110cm below the tank surface level would slow down the flow return rate considerably. So what I'm wondering is what size of external filter should i go for? The test was just me trying to work it out but using an internal filter which is probably not as powerful.

 

[rabbut]

Ah, ok, sorry about that..

For a 55g, I'be be looking at one of the following filters;

Eheim 2028
Rena XP2
Tetratec EX1200.

Personally, I prefer the Tetratec's, but it's up to you, they are al good filters. External filters to avoid IMO would be Fluval due un-reliability and AquaOne due to poor parts support now as a result of them no longer producing spares for their filters AquaOne filters are reliable, but if you loose a seal ring after 3-5 years due to normal wear and tear, you'd ave to scrap the whole filter over a £15 parts replacement job...

All the best
Rabbut

 

[sonicfish73]

Ah, ok, sorry about that..

For a 55g, I'be be looking at one of the following filters;

Eheim 2028
Rena XP2
Tetratec EX1200.

Personally, I prefer the Tetratec's, but it's up to you, they are al good filters. External filters to avoid IMO would be Fluval due un-reliability and AquaOne due to poor parts support now as a result of them no longer producing spares for their filters AquaOne filters are reliable, but if you loose a seal ring after 3-5 years due to normal wear and tear, you'd ave to scrap the whole filter over a £15 parts replacement job...

All the best
Rabbut

When you say the Fluval make is unreliable, do you mean it's prone to breaking down. I had my eye on the 305 model as well but now I'm not so sure. Would hate to change my filter system for something that may or may not fail. Anyone else had probs with this model?

 

[three-fingers]

Fluvals are very popular filters, Rabbut hates them though, and you can do a search of his post to see why (wont take long ).

Then look at this thread lol: http/www.fishforums.net/index.php?showtopic=271050&hl=

And because I don't want to type it out again, read an old post of mine here: http/www.fishforums.net/index.php?s=&amp...t&p=2509663

IMO any external from a decent brand name will be great as long as you maintain it properly (lubricate any rubber parts every few months, especially the o-ring and check the impeller).

You pretty much get what you pay for with externals IMO, so just avoid brand names youve never heard of, and some brand names are justifiably more expensive than others (like Eheim).

I have a Fluval 305 that's been great so far for over 2 years, and a Fluval 105 for over one year.

 

[rabbut]

I'm of the conclusion that all QC fails are sent to Leeds. Most of works customers that buy Fluvals have issues at or just after the point of the warrently running out, or in the first week of ownership.

I ran a Fluval 404 (second hand but fitted with a new Aquastop, main seal ring and impeller by myself on purchase) and it ran like a freight train, killed the impeller, leaked from most places imaginable (and a few that weren't ) for seemingly no reason and clogged very quickly during the 4-6 months I was running it. After it started to give out electric shocks, I retired it. It's Mean Time Between Failure was about 4-5 weeks...

A mate of mine had a 2 month old 405 drain literally half the contents of his 90l tank onto the floor in all of 30 seconds while he crossed the room and closed the Aquastop. The main seal had snapped Someone on here I donated mature media to returned his 205 after two days due to leaking. Work's three year old 305 has needed two new impellers, three main seal rings and god knows how many new Aquastops since purchase. Thankfully all it's new parts have been replaced under warranty and hence all the new parts we get free, but it's gonna be an expensive bit of junk, oops sorry, I mean equipment, parts wise now it's left it's warranty period The priming pumps on them only work 2-3 times also IME...

All this said, I know one happy Fluval user... But several Fluval users, easily in the double figures, that are un-happy about premature parts failures.

Let's hope the new Fluval G series is better. Tenner says it's more shiny $*** that has been given more thought to how it looks to how reliable it actually is like the 05 series (and you can tell not much thought went into looks either). Mind you, the FX5 has been good thus far, and that has been brought out since the 05 series, so they may now be on-top of the reliability *issues* in the new models...

All the best
rabbut

 

[three-fingers]

I ran a Fluval 404 (second hand but fitted with a new Aquastop, main seal ring and impeller by myself on purchase) and it ran like a freight train, killed the impeller, leaked from most places imaginable (and a few that weren't ) for seemingly no reason and clogged very quickly during the 4-6 months I was running it. After it started to give out electric shocks, I retired it. It's Mean Time Between Failure was about 4-5 weeks...

The scary part of this story is that you sold it as being in "very good condition".

http/www.fishforums.net/index.php?showtopic=246135&hl=

 

[rabbut]

That filter was a mates that was given to me cheaply for repair and sale after becoming noisy. At the point of posting that advert had just had a replacement impeller and and a thourghour clean following a full check to prove it was working and water proof, and hence was in very good condition