2 Filters, Problems, Flow Etc

[Fish'nchips]

I recently moved house and the internal filter which I had painstakingly glued in place busted off again. It was glued to stop small fish getting trapped behind it. (It is a juwel internal box thing that contains a heater and pump head.)
This runs in conjunction with an external filter but I really like the two filter combo as it provides the extra boost of flow for plants and the tanks recovers real quick from house-moves with two filters going. (like this last move I only got one filter up and running real quick and the other a couple of days later - I have the extra flexibility).
Anyway, I decided the internal juwel has to go. Can anyone recommend something else I can put internally instead of it. Must not suck up baby fry so am avoiding a "fan" thing. Must not let small fish get stuck behind it. Is only supplemental to external filter so sponge filter will do fine? The old FLUVAL 4 comes to mind, but their current offering seems to try and incorporate media in a small filter box, seems weird. Looking forward to hearing from you.

 

[Vethian]

what about an external overflow?  its a cheap DIY made from PVC.  then you can put a sponge over the intake.

 

[Akasha72]

why not run two externals? It's how my tank runs, I have one in each rear corner and I have a lovely flow and it means I can maintain each filter on a cycle so if I get over enthusiastic on cleaning day (which is rare but it can happen) the other filter picks up any slack.

 

[Bubbelzzz]

There are filters that you can hang on the glass. This is actually a sort of small external filter. 
 
You could also have a look at eHeim internal filters. These filters can be placed with suction cups and have plenty of space behind them to avoid that fish are being trapped behind it. 
 
You can pull a stocking over an filter inlet to avoid fry or baby shrimps being sucked into the filter.

 

[Fish'nchips]

Thank you for all the ideas. I'm going with the eHeim filter, placed an order for the BIOPOWER 240.
Hopefully this will be the end of all my filter box problems. I might use some of the sponge out of the juwel box to create a sponge "sheath" for the bottom of the eHeim.

Fish Herder, two externals sounds great, but I've never understood one in each corner, as regards trying to get a circulation in the tank?

 

[Essjay]

I have the biopower 240. The sponge that goes in the bottom container does fit quite snuggly and I don't think small fish, even fry, will get sucked inside. That container is the only one in the filter with slits. I have the aquaball filter, which has similar sponges and slits, in the tank with cherry shrimps and not found any baby shrimps caught in that filter.
And fish won't get stuck behind it. I have ember tetras and neon green rasboras (Microdevario kubotai) in this tank and they haven't got stuck.

 

[Fish'nchips]

OK, thank you for the added re-assurance. Looking forward to receiving it. I checked on eBay and people are selling their old juwel boxes and power heads and some seem to be selling. Not sure if I'm missing something there. I can't see it coming in useful for anything and I have the bad habit TO collect all sort of bits for future use??? hmm

 

[Akasha72]

Hi again, I have a Juwel Rio 240 tank which is 4ft long. I run two external filters - one in each rear corner. The inlet and the outlet for each filter are on the same side (helps with maintenance not to have pipes crossing at the back of the tank) I have my outlet nozzles facing into the centre so the flow is hitting the middle top of the front glass. The flow then turns back on itself and any debris is sucked in by the inlet. I have a great flow and very little in dead spots where debris collects doing it this way. This tank has been running this was for almost 2 years and I wouldn't change my filter positions for anything. It's a system that works
 

unfortunately you can't see the filters in the photo due to my clever planting to hide them! but you can see the surface movement with the bubbles on the surface.

 

[Fish'nchips]

I guess you've found a way that works with those filters. I imagine it was quite important that they were the same power as eachother as I can imagine all kinds of weird interactions if they weren't matched, knowing how complex water dynamics are. Nice look plants and aquascaping by the way. I think I might have to record the progress of my tank re-scape but it wont be for a while as I have to move again soon. When I have moved I'm keeping the plants I have but switching to blue slate substrate (easy to get I live in Cornwall) and either blue lamp or actinic lamp.

 

[Akasha72]

the power doesn't seem to matter. Currently I have 2 JBL crystalprofi e901's - both the same filter but only one of them is new to this tank. Up until 6 months ago I had one of the e901's and one e701 (the filter below the e901) The e701 started making an awful noise and I thought I could smell burning intermittently so I decided to replace it. I just happened to replace it with the e901 because it gave me a larger filter with more options.
 
Want matters is the flow direction. I used to get dead spots and so debris would congrigate in various spots around the tank. I also used to get a greasy film in the opposite corner to the filter outlet (this was when I just ran one filter) so to combat the greasy film I added a second filter - this cured the problem. Then I began playing around with direction of the outlets and having the flow hitting the front middle wall seemed to be the one that picked up the debris the best. My filter baskets are always covered in bits of leaves etc and there is always a very small amount of sand in my filter on cleaning day. The filters are doing their job well 

 

[Fish'nchips]

My filter has arrived. I've not unpacked it yet as it's for my birthday. I'm very excited!

 

[BiggTexx]

I imagine it was quite important that they were the same power as eachother as I can imagine all kinds of weird interactions if they weren't matched, knowing how complex water dynamics are.

Since filters are not connected to each other, you can run very dissimilar filters together with no ill effects.  For example, a 100 GPH HOB filter and a 360 GPH Canister filter work fine on the same tank. The only thing you need to worry about is the current created and whether your fish prefer a high or a low current (water movement).  For example, a Betta would prefer as little water movement as possible.

 

[Fish'nchips]

Since filters are not connected to each other, you can run very dissimilar filters together with no ill effects

No - I didn't mean that, after all, I am running two completely different filters. What I meant was, to be able to see these two flows meet each other in the middle of the tank predictably, from two filters pointing directly at one another, and without some weird flow patterns, I would have set about with two filters the same. But apparently not.
 
I can see how you assumed this, especially with the title of this thread, but it was more of a side issue, about running filters from either end towards each-other and I assumed the power of each, in this case, would be much more relevant.