question about filters

wckdkl0wn;1869102; said:

I've only ever used HOB type filters. Never used a canister or a sump. But after reading a bit I was curious if I used a sump, would I still need another type of filtration or would the sump take care of it all?

How big would the sump have to be for a 125gal? Should I get an over flow for the tank and do it that way or just a siphon? I would like to pull from midlevel of the aquarium and not just skim the top.

I did notice that overflows had gph listings. If I got a 900gph max intake overflow what pump would I get? Would I match it the same or go more or less?

Like I said I have never used this type of filtration before. Any help would be great.

Click to expand...

yes, a sump will take care of all your bio filtration and some of your mechanical filtration depending on that you put in there. i put filter floss in my sump and it does an ok job of catching particles. you could add a canister filter if you want better mechanical filtration.

as for sump size, i think a 30g sump would be fine. what do you mean by a siphon? there are 3 ways that i know of to sucessfully get your tank water into your sump. they are:

- built in corner overflow box, tank needs to be drilled
- hang on overflox box (this is what i have, i have a CPR unit)
- DIY overflow made out of PVC piping

i'm not sure if pulling water from the middle of your tank would work, because when the power goes out, you tank would keep draining and your sump would flood. this is why overflows are designed to skim the top of the tank. when the power goes out, only an inch or two of water will drain into your sump and it wont flood.

i think a 900 gph pump would be good for your tank. you can go less, but certainly dont exceed the gph ratings according to your overflow unit

hope this helps!

wckdkl0wn;1870732; said:

CPR unit? What is that?

Also I am liking the idea of the pvc diy overflow. I think this system will be a lot cheaper then buying a canister right now. Basically I have the tank sitting completely empty. I want to get this tank up and running as cheap as possible for now and add to it later.

My stand is able to hold 2 20-30 gallon tanks under it so that size would be perfect then.

Would I be able to run more then 1 sump? Say 2 20 gallon tanks? I can pickup 20 gallon tanks for $6 each. Just set them up as stand alone from each other and have one draw water from one end of the 125gal and the other draw from the other with pump in each tank. Input?

what does mechanical filtration do? Mainly water movement? if thats the case I could just put powerheads in right?


Also what is my ideal gph for this big tank?

Click to expand...

CPR is just a brand of overflow boxes. They are neat cause they dont lose their siphon when the power goes out. when power comes back on, they start up instantly and need no "priming" to get the air out.

Im sure you could run more than one sump, but if youre not gonna have the bioload to support the bacteria in 2 20g sumps, youre just wasting your money. with the money youd spend on building another sump and the pump to run it, id suggest just getting a fluval or rena canister filter that will give you more mechanical filtration. i have a similar setup on my 210; a big sump and an FX5.

and mechanical filtration refers to mechanically cleaning the water, doesnt refer to only water movement. mecanically filtering the water is commonly done through sponges, filter floss, filter brushes etc. in this type of filtration, water is passed through certain types of media that will TRAP particles and debris thus making your water clearer.

biological filtration, on the other hand, does nothing to visibly clean your water of suspended particles. the media (scrubbies, bio balls, etc) in your sump will grow bacteria to keep the ammonia and nitrite levels in check. its sort of an invisible form of filtration since you cant visibly see nitrite and ammonia.

this is why is suggest doing a canister and a sump instead of two seperate sumps. the sump will give you all the bio filtration you need and the canister will give you the mechanical filtration to keep your water clean along with a little extra bio filtration.

for a tank your size, id say to use about 600~900gph of water movement. i actually have 1000gph of movement in 210g, not including my FX5