# Help in choosing size of canister filter



## ghosh_demox (Dec 13, 2014)

Hi,

I have a 425 litres (5 ft long) fish tank with cichlids. Am looking for a canister filter.

Experts can you please suggest minimum how many liters per hour filter should I be looking at for good filtration?

Thanks,
Amit


----------



## BDASTRK (Dec 12, 2014)

This will be very interesting to hear the responses form the "So called experts" I can tell you from my experiences that I use a simple mathematical equation and it this. My total mechanical and bio filtration has a flow rate of 20 times per hour change over. I run 12 x gallons per hr on the mechanical side and 8 x gallons per hr bio side.

This is pump output at 6ft head height on my tank, what it does not account for is the about of head pressure from the 90's and 45's in the plumbing but its close enough and has worked for me over the years without any issues. I am of the belief that more is always better then less.

So if you use the simple Gallons of your tank and you times is by 12 thats mechanical and times it by 8 thats your Bio. These are my minimums and have worked for 25 yrs now. I dont recall ever having any issue's over the years.


----------



## Kanorin (Apr 8, 2008)

All of my filters combined process 9x the volume of the tank in an hour. The advice I've heard is to shoot for 8-10 times turnover per hour. 20x turnover would be even better, but many people don't have the money to buy that much filtration.

How many fish are you planning to put in this tank?


----------



## dsiple3 (Mar 4, 2014)

BDASTRK said:


> This is pump output at 6ft head height on my tank,


With a canister filter there is 0' head if the intake and return are on the same tank.

I am by far not an expert, but I do try to have 8-10 times turn over if I can afford it. Before I upgraded tanks, I had almost 11 times turn over. Now I have 5 times. I do see a slight decline in my water clarity for that.


----------



## Loume (Dec 27, 2014)

I guess you are looking to add a canister filter to another form(s) of filtration. If not, and if I were you I would be looking to divide your needs into 2 or more canister filters, it's so much more peace of mind in case one of them needs to take up the slack of the other, for cleaning, breakdown of one, etc., especially in crowded tanks.


----------



## noddy (Nov 20, 2006)

Sounds very close to two of the tanks that I have, 5' 120g. I run two Eheim 2217s and a double stacked #5 hydro sponge on these tanks (I only use the sponges for polishing and water movement. I rinse them out in tap water). I have also ran the same tanks with only sponge filters. I'm talking about heavily stocked Tropheus and petro tanks. If you'r thinking about only one canister, I would suggest an Eheim 2262, I have two of these on my 210g tank.


----------



## Deeda (Oct 12, 2012)

Hello Amit and Welcome to C-F!

What type of filter(s) are you currently using?

What brand and/or model canister filters are available in your area? Do you have a certain amount of money you are looking to spend on a canister?

There is no hard and fast rule for choosing any filter based on it's listed flow rates. Stocking levels, adult size of the fish, tank size and other factors all come in to play to help choose an appropriate filter. When I first started keeping Malawi cichlids, I had the same questions and bought a canister filter rated for the tank size based on the filter manufacturer's suggestion. It worked well until the fish started to mature so I bought a second, larger canister that improved the water flow throughout the tank and helped remove more debris that was visible in the tank.

I like to monitor the tank water parameters using test kits to see if I have enough filtration to handle the bio-load of the tank. Canister filters also need to be maintained properly by cleaning (in tank water) the mechanical media and sponges and rinsing any bio media (in tank water) to remove debris that accumulates in the filter.

Can you provide more details on the dimensions of your tank and your current fish stocking level?


----------



## BDASTRK (Dec 12, 2014)

dsiple3 said:


> BDASTRK said:
> 
> 
> > This is pump output at 6ft head height on my tank,
> ...


The head is calculated on the distance the pump must push to water to its exit point, it has nothing to do with inlet and outlet. My top of tank is 6' 6" tall and my pump discharges at 6" off ground, therefore I have a 6' head height. What comes into play on actual output is the restriction of 90's, ball valves, 45's etc. These all cause additional restrictions in the water flow and actually decrease in output because of it.


----------



## dsiple3 (Mar 4, 2014)

BD, I'll just agree to disagree. To my information, head is from source water level to pump's maximum or desired height to pump water, not from pump location to desired water level, given that there is only 1 tank and minimal twists and turns in plumbing. This is why the pressure on the impellor is the same regardless if the pump is on the floor or 2 inches below the waterline.Water equalizes in the lines when the pump is turned off. That equalization shows the level at which head caalculation begins. This translates in little to no discernable loss in pressure at the return pipes highest point, given an average tank setup. This is why when you look up most canister filters there is no head chart given. I see that only on free standing pumps like those used in sumps.

That being said, I agree with Iggy in that bioload is a necessary concern when looking at filtration. As I mentioned earlier, my water clarity recently dropped slightly. In my case it is either the bioload went above my filtrations abiliity to properly maintain water quality, which I am testing for, or my polishing pads need to be replaced.


----------



## BDASTRK (Dec 12, 2014)

Well Again we will have to agree to disagree, been doing mechanical engineering my whole adult life, if you want an education of pumps go to Gusher pumps, its all ther for you to completely understand. Truth be told, the gravity in which you are referencing in the pump world works only in a syphon mode, this is overcome by the motor and impellor, the feed source has nothing to do with the head height when using jet propulsion.

Bio is a major part of the equation for sure, but when you break it all down I want more mechanical to handle the amount of waste that is generated by overstocking which I always do. This is why I say set the tank up for worst case scenario. Aside of the Nitrate issue's I run into (Tap water being a big part) of my issue which the De-nitrate filter took care of that this method has worked well for every situation I have run into for 25 yrs now. I am a all in guy though, I don't 1/2 ass anything or I just wont do it.


----------



## Loume (Dec 27, 2014)

You both bring up good points, but this is the way I think it. You can't call it 6' of head loss, when it's drawing and returning from/to the same points, but then even ignoring the friction losses, you can't say it's zero head either, the reason being, it's not a closed system, and once the water is returned to the tank, it's no longer under pressure to force back down the intake. Unless the pump is very small and the tubing large, gravity is not going to supply enough on it's own, and there is a going to be a suction pressure on the pump. Maybe I'm wrong, but I think the reality of the head loss would be somewhere in between those figures.


----------



## hisplaceresort1 (Mar 10, 2014)

I'm not an expert, but I thought perhaps you'd like to hear a mere mortal's perspective, too... 

...I have a very overstocked 75gallon. I run 2 cascade 1500's with various biomedia, and it wasn't enough, so I added 1 Fluval 405 with coarse sponge and polishing pads only, and even left 1 tray empty. The intake of the Fluval is behind the intake to one of the Cascades, in relation to the water flow, so more of the poo goes into the filter with biomedia.

I'm also waiting for a couple of circ pumps I ordered to move help move that poo even better! With the 3 pumps, it's about 1100 gph when they're clean, or approx 14.67 times/hour. That drops as they become dirty, of course.

I dare say that since most of us have nearly the same height stands and put our canisters below the tanks that keeping them maintained is at least as big of a consideration as head pressure loss... One thing I don't think has been mentioned yet - clean those hoses when you clean your canisters! It makes a huge difference in the flow...

Nitrate's still gonna be your biggest challenge, probably... I am taking some good advice, (thanks BDASTRK!) and will soon be adding a denitrator.

So, it comes down to what works for _you_.

Look at 8-10x as a relatively safe place to start, and if it's not enough - just be prepared to add more. Not all of us have really deep pockets, but I watched Craigslist, and got an older Fluval 405 thrown in when I bought my used tank. (I paid $150 for a 75 gallon in really good condition, a solid, albeit ugly, stand, glass lids, a Marineland c220 with some missing parts, a Fluval 405 with some missing parts, and a hood light.)

$60 in missing/replacement parts, pads & sponges and the Fluval's like new.

So, my point is that it doesn't have to cost you an arm and a leg to add more filtration if it turns out that you need it. And like me, you'll know when you need it... Let us know how it turns out! opcorn:


----------



## ghosh_demox (Dec 13, 2014)

Deeda said:


> Hello Amit and Welcome to C-F!
> 
> What type of filter(s) are you currently using?
> 
> ...


Hi,

My tank size is 60"(L) X 19"(W) X 24"(H). The stand is 30" high.

I am using a submersible filter with a flow rate of 1740 litres/hour. I used to have 2 oscars (12"), 3 green terrors (7"), and 4 tin foil barbs in this tank. Due to house shifting I gave away those fish. When I setup the tank again I thought of trying out african cichlids. So this is my first time with Arfican cichlids. I have the following in the same tank now but am finding it difficult as I can see a lot of debris on the gravel and also algae growth on the glass and have to end up doing gravel cleaning every 5-6 days.

2 VC-10 (3")
2 zebra obliquidens (3")
2 malawi eye biters (3")
3 dragon blood (2")
4 electric yellow lab (2")
2 red kodango (2")
2 dolphins (2.5")
4 other peacocks ( mostly sunshine yellows 3")
2 plecos (3")
Plan to add a pair of red empress and a pair of taiwan reef

The major canister filters available in my area a EHIEM (quite on the expensive side), SunSun and Dophin (http://www.kwzone.com/products/links/ca ... filter.htm). I am considering the Dophin C1600 model, fits my pocket. But reading at some of the comments looks like C1600 is not going to be adequate, also please share your experiences if anyone is using/used Dophin filters.

Thanks to all you guys for your valuable advice,
Amit


----------



## Deeda (Oct 12, 2012)

Hi Amit, I do not have the fish that you are currently stocking so I'll let others make suggestions.

I am familiar with many models of Eheim filters but have heard good reviews of various SunSun canister filters. I also have not heard of Dophin brand filters but I don't see why the model C1600 wouldn't work for your tank. It appears to have 5 trays for various media so it would allow you to choose how much and what kind you want to fill it with.

Gravel substrate usually needs to be vacuumed at least weekly because it is easier for debris and uneaten food to get trapped between the gravel. If you have sand available near you and you like the way sand looks in the tank, you may want to consider trying it. Many people use Pool Filter Sand (PFS) which is a product designed for swimming pool filters, hence the name.

Algae could be the result of having the tank lights on too long, exposure of the tank to the sunlight from outdoors or being near a window or by the chemical makeup of your tank water.

When you decide to add another filter, keep the existing internal filter in operation for at least a few weeks to allow your new filter to build up a good bacteria colony. I would probably even continue to operated the old filter because it seems that you will be fully stocking this tank.

Another option for helping to move debris off of the substrate is a power head or circulator though it does take some time to figure out the optimum placement in the tank to keep things stirred up so your filter can catch them. I'm not a big fan of using them because they are so obvious in the tank.


----------

