# Help with setting up external filter please



## Eriya

Ok, so my new Tetra tec EX1200 external filter arrived a few days ago (man, it is massive!) and, as someone predicted, I do have a few questions regarding the setup.

1) This question actually comes from my boyfriend: would having this filter mean we can clean the tank less often? Currently we do 15-20% changes once a week and my tank is 98L.

2) Would it be necessary to have an air pump and air stone? I do have one just now, and one of my goldfish does actually like to swim downwards against the bubbles sometimes, so I would keep it, but just wondering in case it broke down - would I have to get a new one ASAP or would I not need one with the filter?

3) As I can't swap the filter media from the old filter (completely different format), I will be running the two filters at the same time for a while. My question is - how long should I keep the two filters running together?

4) The manual tells me how often to replace the filter media (oh, the strain on my wages! :O) but it doesn't say how often to just clean it in tank water. Should the filter media be cleaned once a week or less often?

5) Now I hope this one makes sense.. I was just wondering how low does the intake pipe (strainer) need to be? Should it be almost touching the gravel or a bit higher than that?

6) Again, I hope this makes sense. The manual tells me to "adjust the length of the spray bar (flow return pipe) to the width of the tank". I guess I'm wondering if that means I should have it at 20cm if the width of the tank is 20cm, even though it is shown to be attached to the "length" of the tank?

7) The picture in the manual shows the spray bar above water level. I was just wondering if that's how it has to be, or if the spray bar can be underneath water level?

Hope this isn't too confusing! I will be setting it up tomorrow, so wanted to be as knowledgeable as possible


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## NaomiM

Congrats on the new filter. I don't have an external myself, but I'll have a go at answering some of your questions!

1) Weekly (at least) changes are always recommended a) because you need to hoover up the poo etc regularly and b) because little and often is less of a shock to the fish than infrequent large changes. If you go onto AqAdvisor - Intelligent Freshwater Tropical Fish Aquarium Stocking Calculator and Aquarium Tank/Filter Advisor and enter the details of your tank, stock and filter, it can give you an indication of what size water changes you need to do each week.

2) Oxygenation takes place at the surface. Bubbles in the water don't add oxygen (though they may look pretty and the fish often love swimming in them!) so the only benefit oxygen-wise of the airstone is the extent to which it agitates the water surface. If the filter's providing plenty of surface agitation, an airstone/pump aren't necessary. At times when extra oxygen is required, however (e.g. in very hot weather, or if you have meds in the water, or if the tank is overstocked), then it may help a little with this.

3) You may get different answers from different people on this one, but what I'd do would be to give it a couple of weeks, then gradually start removing media from the old filter, doing frequent water tests to make sure ammonia and nitrite stay at 0. If they do spike a little at any point, don't remove any more until it's stabilised.

4) Ignore the instructions about changing the media, that's just to make money! Depending on what type of media you have, there may be a top polyfoam pad that needs replacing every now and then, but not until it's disintegrating. For the rest, just give ONE of the sponges or baskets of ceramic media a gentle swish in old tank water every couple of weeks. Don't clean all the media at the same time, and don't throw anything away unless it's really falling to pieces!

5), 6) and 7) Not sure, sorry - maybe someone with more experience of externals can help you here!


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## magpie

1) Afraid not, weekly 20% water changes will still be necessary to lower the nitrates and a few other things that the filter won't be able to get rid of.

2) You don't need to have an air pump & stone at all if you don't want them. The only thing they do is create pretty bubbles and a bit more movement at the surface which can help with oxygenating the water a bit. The filter is vital though 

3) Hmm, that one I'm not sure about. I'd probably say at least a few weeks, maybe even a month or two just to be sure?

4) Ignore the manual if it tells you to replace the media. You don't need to do this until it is literally falling apart, which could take years. I have exactly the same media in my TetraTec EX1200 as I did when I bought it, which must be about 5 years ago now. Except I put a bit of filter wool on the very top which I change every now & again as it gets really grubby.

I probably clean my filter media once every 2 months maybe? Depends on how heavily stocked the tank is though.

5) I don't think it matters hugely, but fairly low. Mine is about 4-5 inches off the gravel I think...

6) Again, I don't think it really matters, and depends on where you prefer to put the spray bar. In the past I've had mine both along the length of the tank and along the width at some stage, it doesn't seem to make much difference.

7) Under is fine  Though I'd angle it slightly upwards, so that it creates more of a ripple on the surface of the water. Again, like with airstones, more surface agitation helps with gas exchange.

Hope that helps 

Edit: Naomi beat me to it! I obviously type very slowly!


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## Eriya

Thanks a lot to both of you  I did think weekly changes are still necessary, but now I can prove it to my boyfriend by telling him petforums people said so ;P He's the one who cleans the tank most often (as I clean the rats' and gerbils' cages) so he obviously wanted to try and get away with doing it so often 

I'll leave the air stone and pump in as one of the fishies does like it from time to time but it's good to know it's not necessary.

There's only one filter media in the old filter. It's an AquaEl internal filter. No idea what type etc as it just came with the tank. So I think I'll just leave them both in for two months or so before I take out the old one. Just to be sure.

I had no idea that you don't need to change the filter media!!!  And to think that I used to feel so bad when I didn't buy new media by the specified time frame!  Thank goodness though, as it would put quite a strain on pet money. This is why petforums are a good place to be 

Can the intake pipe/strainer be as low as 5cm from the gravel? Just wondering, as my tank isn't too high.

Glad to hear the spray bar can be positioned under the water level


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## magpie

As Naomi said, the instructions about changing the filter media seem to be just a money-making scheme. Filter sponges, ceramics & bio balls all last for ages, there is no need to change them until they fall to bits.



Eriya said:


> Can the intake pipe/strainer be as low as 5cm from the gravel? Just wondering, as my tank isn't too high.


Don't see why not  I would think it'd make for better water circulation, to have the inlet pipe low and the outlet pipe high.


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## NaomiM

BTW, if you have carbon media in your filter, I'd take it out and replace it with more sponges/beads. Carbon is of no use unless you want to remove meds from the water, and adding more 'normal' media instead will allow more surface area for the good bacteria to grow


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## Eriya

One more question. Am I supposed to remove the stopper from the spray bar or not? It says to remove it to decrease water pressure in the spray bar but on the pictures in the manual it looks like the stopper is still there when running the filter.


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## magpie

You mean the stopper that goes on the end of the spray bar? Leave it in. Not really sure why they'd say to take it out, as then the water would just flow out the end instead of the spray holes... and that kinda defeats the point of a spray bar!


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## Eriya

magpie said:


> You mean the stopper that goes on the end of the spray bar? Leave it in. Not really sure why they'd say to take it out, as then the water would just flow out the end instead of the spray holes... and that kinda defeats the point of a spray bar!


That's what I thought! Physics wasn't my strength at school though that's why I thought I'd double check  Thanks again!


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## Eriya

Woohoo! It's all set up and running now  Took some trial and error and lots of water splashed all over the place (the result of testing the filter with the spray bar tilted upwards and the tank still half-empty) but it's all done now! So happy. I love projects like this. So glad to think my fishies should be happier now


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## Eriya

This is a silly question and I thought there's no point starting a new thread for it. The stopper from my spray bar (flow return pipe) fell off and now won't stay attached to it, it just seems loose.. This means that the pipe isn't doing it's job properly, when it comes to aerating the water. Has anyone got any ideas on what I could use to substitute the stopper or make it stay put?


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## magpie

That happened to mine too! I used aquarium silicone to glue the stopper in place, though obviously that means you can't ever take it off again


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## Eriya

magpie said:


> That happened to mine too! I used aquarium silicone to glue the stopper in place, though obviously that means you can't ever take it off again


I was thinking about doing that. Thanks for the advice, I'll probably just do that, as it's really annoying me how it keeps falling off, haha!


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## Phoenix24

I only just saw this thread, and the advice you have had so far is excellent. I just wanted to ask something though - why is the filter media from the old internal no good for the new external?

Most externals I know of have media that sits in baskets. All you have to do is add the old media to the baskets on top of the new media. In fact, if you have a basket just with carbon in, which you will have removed, then that whole basket is free for your old media.

I used to have the Interpet PF3 Internal (which was AWFUL, worst filter ever) and upgraded to the Aquael Unimax 250. In one basket there is a single sponge, and space (presumably) for the carbon to go in that basket with it. Instead of the carbon all the old sponges from every internal I have ever used is in that basket, which is very useful for me because every time I have to set up a hospital tank I just borrow one of the spare sponges and pop it in one of the old internals (i've had several).

Spare bio media you just shove in the same basket with the rest.

By the way, if you have zeolite media that is like the carbon, you shouldn't leave that long term in the filter. Zeolite is great for mopping up ammonia when there are problems, but afterwards it eventually leaches it all back in. It then becomes, essentially, like the biomedia. My LFS owner advised I remove the zeolite and fill that basket with more bio media to increase filtration capacity.

Some of the pipes they send with the externals are pretty flimsy. You might be able to contact the manufacturer and tell them the pipe broke within days of setting it up, and they might send you a spare free of charge. If not, you can normally buy spare pipes. Though the silicone will do the job just as well.


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## Eriya

Thanks for your advice Phoenix24, but I've had the new filter since July, so already got rid of the old filter and old media. I guess I just assumed that, because the new and old filters were not compatible I couldn't use the old media in the new filter. I sometimes have a very narrow and rigid perspective on things.

I don't think I have zeolite media, unless there's another name for it.

The stopper only became loose a few weeks ago and to be honest I can't be bothered contacting the manufacturer, as it's nothing too serious that can't be repaired easily


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## Phoenix24

Oops, didn't see the dates on the posts - but at least you know for future reference that you can keep old media in an external in the baskets. 

Hope all is working out nicely in your tank then - externals are brilliant once all set up (quite a hassle to set them up though...)


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## Eriya

Thank you


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