Question about using two filters?

I currently have an overhead filter on my 20-gallon freshwater aquarium, but I'm planning to have another filter for extra filtration. I want an undergravel filter, but I'm thinking that it might be bad because the water will flow in two directions: down to the gravel and to the overhead filter. What do you say? Can I use an undergravel filter, or will the overhead filter will do without another filter?

 

Underground filters are really not recommended because of all the stuff that gets pulled under the plate. It's almost impossible to get all the gunk vacuumed out.
By overhead filter do you mean a Hang on the back filter(HOB))?
Carol

 

My tank came with an under gravel filter and I purchased a canister. It works great but Butterfly is right about the UGF. You really have to keep it clean. That means either changing a lot of water throughout the week or buying a gravel washer that doesn't remove the water. I use an Eheim Sludge Extractor every few days to keep up with the waste build up. As well as weekly water changes with a Python Gravel washer. Granted that's a MUCH larger tank than yours so both those items might be a bit big. There is another smaller one that may work. The Hagen Marina MultiVac. Much smaller and not as powerful.

My recommendation for adding extra filtration is to go with either a hang on back or a canister. Canisters are kinda big for a 20 but something like a Rena Filstar XP1 would replace all your filters. You wouldn't need the HOB you have. Depending on your tank and habits, it may be unnecessary to add more filtration. Is there any particular reason you want extra?

Here's a link to the Filstar XP1


I use four Filstars (2 XP2s, 1 XP3, and 1 XP4) You could say I like them.

 

Lyndatu, you should read this thread:

I also think canister filters are too powerful for a 20 gallon tank, but I guess an "XP1" would be fine It pumps 250 gallons per hour, and you typically need a filtration level of around 10 x the volume of your tank per hour. And over-filtration is always better than under-filtration.

If, however, you decide on some external HOB power filter, I always recommend to people Aqua Clear filters - they're my best filters ever An "Aqua Clear 50" would be good for your tank - it pumps 200 gph (exactly 10 x the volume of your tank).

P.S. You don't need to use the XP1 or the Aqua Clear 50 with the current UG filter you have. I mean, you can if you want to, but you don't have to. XP1 or Aqua Clear 50 alone will provide excellent filtration for your tank. AND ... you'll be able to clean your gravel without problems - no fish wastes will ever again be trapped in your gravel. I'd personally never use any UG filters (as I've said in the link above).

I use four Filstars (2 XP2s, 1 XP3, and 1 XP4) You could say I like them.

I, on the other hand, don't really like my XP3! It's actually the loudest filter I've ever had. I don't know if it's just me who got some faulty model, or are they this loud? No matter how much I cushion the filter's base, it's still very loud. Not to mention the filter's base is rubber, so this alone should make it quiet. That's why I'll never get an XP again. It looks like it's just my experience that's bad, because many people are saying XPs are very quiet filters.

Besides, I find canister filters much more difficult to clean than external HOB power filters (such as Aqua Clears). With all of the tubing and hoses in a canister filter, and the taking out of the heavy filter box from the inside of the stand, carrying it to the sink, etc ... is so much hassle. With the Aqua Clear, you just take the basket by its handles out of the filter, clean it, and you're done. Literally 5 minutes of work. Not so with the XP3! Plus, it's very hard to clean the inside of the long hoses of a canister filter. No such need with my Aqua Clears.

Anyways, that's just my experience and opinion

 

You should read this thread:
I'd personally never use any UG filters (as I've said in the link above).

I'll likely be removing the UGF on my 150 next year. It's kinda hard to get out once it's in you know. In June sometime I'll be draining and cleaning it, so it'll be a good time to make that much of a change. It has an XP4 on it so I think I can get rid of the Old UGF lol. I can better position my powerheads with them not attached to tubes. Yep, yur comin outta there UGF. lol

The HOB is plenty. The reasons to go with an XP1 would be hiding the filter and having more space for filter media. It does come with a flow regulator that you could turn down a little if you had too much current. They are kinda pricey though. 70-80 bucks.

 

I currently have an overhead filter on my 20-gallon freshwater aquarium, but I'm planning to have another filter for extra filtration. I want an undergravel filter, but I'm thinking that it might be bad because the water will flow in two directions: down to the gravel and to the overhead filter. What do you say? Can I use an undergravel filter, or will the overhead filter will do without another filter?

I must agree with Butterfly. Our filter systems are used to remove gunk from the water. by using a UGF you are just storing all that gunk in your gravel.
You will remove some of the gunk when you vac, but not all..
My main fear with UGF is septic tank...What would happen if the gravel was full of gunk and the power went off and the gunk started to leach out of the gravel.. With a canister filter, if you lost power all the gunk would remain in the filter
If you go to a UGF with your HOB, try using a small powerhead to mix thing up.

 

What would happen if the gravel was full of gunk and the power went off and the gunk started to leach out of the gravel.. With a canister filter, if you lost power all the gunk would remain in the filter

That's a very good point.

 

Yeah, I once cleaned my old 10-gallon aquarium that's running on a UGF and when I had to clean it fully, I removed the UGF, and a LOT of black gunk spread out. Disgusting. I actually had to pick up all the remaining objects out with my bare hands. Anyway, thanks to you all for your help. I'm not going to use an undergravel filter.

Also, the overhead filter (or trickle filter): it's the one with the big box with filtering material that is placed on top of the aquarium and there is an air pump placed inside the aquarium that sucks the water upward to the box and then falls back to the tank as rain.

Just another question: Since I'm not going to use a UGF, can I use a small airlift filter/box filter along with the overhead filter? I used it once in my old aquarium and the fish seemed to like it. Or, is the overhead filter powerful enough for my 20 gallon aquarium?
I wish the overhead filter is enough, because I don't want my tank to be cramped with the box filter. Also, can the overhead filter do mechanical, biological and chemical filtration? Thanks in advance.

 

Sorry I don't know enough about overhead filters to answer this..
I know the canisters give some flexabilaty in regards to filtration, ie change of media, and use pressure not gravity. I would look at all the options, look at all the pro's an con's, give each a score, and go with what suits YOUR Aquarium best. Look at what you need, how much maintenance is required, cost of filter material.

 

Besides, I find canister filters much more difficult to clean than external HOB power filters (such as Aqua Clears). With all of the tubing and hoses in a canister filter, and the taking out of the heavy filter box from the inside of the stand, carrying it to the sink, etc ... is so much hassle. With the Aqua Clear, you just take the basket by its handles out of the filter, clean it, and you're done. Literally 5 minutes of work. Not so with the XP3! Plus, it's very hard to clean the inside of the long hoses of a canister filter. No such need with my Aqua Clears.

Anyways, that's just my experience and opinion

One I agree with. When I found that the Emperor 400 I bought from DFS doesn't fit my 56g tank (the center support bar is in the way by about 2"), I had to decide whether to go with two smaller HOBs or a canister filter. After thinking about it and doing a lot of reading, I decided that the canister would be more trouble than it's worth to maintain, so I got two Emperor 280s from DFS instead. Easy to maintain, and more filtration capacity to boot.

 

I don't believe you can get more filter media capacity in an HOB. You can fit ALOT of media in most canisters. I would agree about the work involved. It is much easier to pull out a cartridge or basket from the top of the tank, and yes those tubes can be a pain, but I can fit a full liter of carbon or more in one basket of my XP2. (I know I don't need that much just using an example) I personally feel there is much more versatlity in media options with a canister. Especially compared with cartridge type HOBs. I like canisters because I like to use ALOT of bio media. So, I can cram a boat load in a canister. I must say again though that this is just a 20 Gal. so you don't need that much media. A small HOB cartridge type filter would be plenty. I'm just pointing out the option if someone felt they wanted more filtration. Also, a canister adds more water volume to your setup. More water is GOOD.

I've never used or seen in person an AquaClear, but I'm interested. The only HOBs I'm actually familiar with are the disposable cartridge type. (ie the Wally World standard power filter). I still say I can fit a lot more media in a canister.

 

Well, I meant more capacity in the sense of gph, not necessarily actual filtration material. I agree that cannisters usually have a lot more media capacity, but the bigger Hagen and Marineland HOBs also give you more capacity over the usual cheap HOBs. The Hagen Aquaclears are kinda like cannister filters in that they use layers of media in baskets inside the filter. And the bigger Marineland Penguins/Emperors have additional media baskets you can use to fill with pretty much anything. Plus, there are lots of alternatives to the cartridges out there, since the brand is so popular.