Additional Filter - Advice Please

[silverchild23]

Hi all

I have a 240L Juwel Rio Tank with an Eheim Pro II 2026 external filter.

As much as I'm really happy with the filter, I'd like to get that water spotless. What would people recommend as a second filter - bearing in mind I have very little cash at the moment? Plus - I'm not sure if it's possible, but is there a filter that lowers nitrates?

Internal / External / Size / Type

Any advice would be greatly appreciated.

 

[raptorrex]

Hi all

I have a 240L Juwel Rio Tank with an Eheim Pro II 2026 external filter.

As much as I'm really happy with the filter, I'd like to get that water spotless. What would people recommend as a second filter - bearing in mind I have very little cash at the moment? Plus - I'm not sure if it's possible, but is there a filter that lowers nitrates?

Internal / External / Size / Type

Any advice would be greatly appreciated.

you could add a small filter to the tank with just filter wool in, this would polish quite well, put will need lots of attention.
i use a little pico filter with a bit of sponge and a load of activated carbon, i never leave it in for more then 48 hours though, and throw away the carbon. but i only do it if i need some really good pictures.

the filter that removes nitrates, is you with water changes. its a bit of a "Holy Grail" some products claim to do this, but as not many use them, my guess is they are either too expensive or don't really do the job effectively. (probably both, lol)

 

[T1KARMANN]

add a small internal filter and put polyfilter in it your water will be spotless buy the polyfilter from ebay its half the price as in the shops

if the filter is small enought you should be able to cut 1 x sheet of standard polyfilter in to 2-3 bits and only need to use 1 bit per month

dont under estimate the power of polyfilter your water will be better than ever after 48hrs

£6.40 for polyfilter on ebay £13 in LFS

 

[Colin_T]

the Eheim should keep your water clean. If not try adding a piece of filter wool to a chamber to catch really fine particles.

The Sera Denitrator will remove nitrates from water but they are expensive to buy and they need to be fed carbon each day. You can buy carbon tablets from wherever you buy the filter. You also need a small water pump to pump a trickle of water thru them. They take a few weeks to start working properly and do work quite well. However, water changes and growing live plants in the tank will help remove nitrates as well.

 

[raptorrex]

the Eheim should keep your water clean. If not try adding a piece of filter wool to a chamber to catch really fine particles.

The Sera Denitrator will remove nitrates from water but they are expensive to buy and they need to be fed carbon each day. You can buy carbon tablets from wherever you buy the filter. You also need a small water pump to pump a trickle of water thru them. They take a few weeks to start working properly and do work quite well. However, water changes and growing live plants in the tank will help remove nitrates as well.

i agree on the external. i only have a cheap hydor prime 30, and unless i need really good close up pics, the water is said by those who see it to be like glass. it seems many do need a second filter to polish, quite why i am not sure.

 

[waterdrop]

OK WOW!, we've got 2 great guys here, T1 and Colin, both of whose TFF answers I've learned tons of stuff from...
We've got 2 great topics (thanks to silverchild)...

1) Water Polishing, Extra Internal Polisher, Eheim/Polisher Question Topic

So my impression is that T1 has a bunch of huge tanks and lots of experience with Eheims and the hobby in general. Thus it makes sense to me that he must have some good reasons and practical experience with this business of adding a small internal as a polisher rather than adding polyfloss to one of the eheim baskets. T1, how bout that? I've always wished I could see a picture of what you're talking about when you say small internal polisher filter. I'd also be quite interested in your thoughts about the xtra internal vs using the main filter -- I can see where it might just be faster and easier solution for the frequent cleaning, is that it or is there more?

2) Sera Bio-Denitrator Topic

This is interesting from two standpoints: First, what I hear Colin saying is that ultimately, at current prices and technology, it probably just still makes sense to do water changes (and to a small extent to have plants) as the solution to Nitrates creeping up. Right Colin?

But secondly I was shocked just to hear of the existence of a device to remove Nitrates. Wow! So I googled it of course and read the Wikipedia entry about the Sera company and then started searching the Sera website. The existance of the "Bio-Denitrator" is confirmed in the Sera company history but I sure couldn't find it as a product. I mean, hey!, don't you think its just interesting from a tech standpoint that the thing exists! How much does it cost? On what principle does it work? It sounds imo more trouble than its worth (although I'm sure the answer might be different for huge aquariums where water changes are a bigger issue to worry about..) Man, I would really like to hear more discussion about it Colin! It feeds right in to a topic I was thinking of starting asking about what the state of the art is currently in replacing various water chem tests with electronic sensors, like the pH controllers that are out there used by the planted tank people.

~~waterdrop~~

 

[raptorrex]

But secondly I was shocked just to hear of the existence of a device to remove Nitrates. Wow! So I googled it of course and read the Wikipedia entry about the Sera company and then started searching the Sera website. The existance of the "Bio-Denitrator" is confirmed in the Sera company history but I sure couldn't find it as a product. I mean, hey!, don't you think its just interesting from a tech standpoint that the thing exists! How much does it cost? On what principle does it work? It sounds imo more trouble than its worth (although I'm sure the answer might be different for huge aquariums where water changes are a bigger issue to worry about..) Man, I would really like to hear more discussion about it Colin! It feeds right in to a topic I was thinking of starting asking about what the state of the art is currently in replacing various water chem tests with electronic sensors, like the pH controllers that are out there used by the planted tank people.

~~waterdrop~~

oddly this was the first listing on goggle rated up to 250 gallons and seems to be the one most have, though there are not many about, strange if it really does do the job it says at an affordable price. cant find the one you mention.: [URL="http/www.petstore.com/ps_ViewItem-Search...rs-vendor-.html"]http/www.petstore.com/ps_ViewItem-Search...rs-vendor-.html[/URL]

 

[T1KARMANN]

you cant beat a small internal filter for polishing the water

if you put filter wool in the external then you have to change very oftern

lets face it who want to be opening up a exturnal filter every month

their is no need to go near a exturnal filter for 3-4 months and with filter wool it may slow the flow down

internal filter clean it once per month job done

fishkeeping is ment to be made as easy as possible with out getting wet then you can sit back and enjoy

polyfilter is the best thing since sliced bread try it unless you try it you will never know

£6 every 3 months is nothing for the results you will get

 

[waterdrop]

thx guys, digesting those replies...

 

[Colin_T]

LOL
Waterdrop's lead-up to this sounded like we were heading for the great debate

The First Sera Denitrator was around in the late 1980s and cost about $400AU. Its newer form was still available a couple of years ago in my LFS for a similar price.
They are a very simple device, so simple in fact I don't know where they get off charging so much money for them. Mine (the first model) was a brown plastic case with a number of partitions in it. In the partitions were plastic filter fibres designed to hold bacteria. The fibres look a lot like the Eheim filter fibres used in canister filters. The case had small hooks moulded onto it that allowed the filter to hang on the edge of an aquarium. I ran mine along the back of the tank. The filter is about 2ft long, 14inches high & 4inches wide.
Water was dripped in one end and went up and down thru the chambers before dripping out the other end. Each day I would drop in a carbon tablet and that fed the anaerobic (lacking oxygen) bacteria living in the filter. The bacteria used the carbon to help break down the nitrates and convert them into nitrogen gas among other things. The end result was clean water, (free of nitrates).
I worked out over time I only had to add 1/4 tablet each day because the load on my tank was pretty low anyway. I also used ethanol for a while and that worked too. Ethanol is alcohol and the bacteria use the carbon in it to help their processes.

The newer models were more square rather than rectangular. They worked on exactly the same principle with water dripping in, anaerobic bacteria eating the nitrates and clean water dripping out the other end.

I recon you could make one out of an old external canister filter. Just have some media in it and have the inlet pipe a couple of inches higher than the outlet/ return hose. Drip water into the inlet pipe and gravity will do the rest. You don't even need the motor running for it.

It takes about 48 hours for the water in the filter to become anaerobic and a couple of weeks before the bacteria have built up in numbers. It's a bit like cycling a tank except you get anaerobic instead of aerobic (requiring oxygen) bacteria living in the filter. Then you require a carbon source.
The carbon tablets were pretty expensive to. They cost about $25AU per container and they only held about 30 tablets, I think. I know it was quite expensive running it hence the reason I only used 1/4 tablet and then went on to Ethanol.

Marine tanks have been using another way of removing nitrates. They use big pieces of live rock. The rock is aerobic on the outer 1-2 inches but becomes anaerobic once you get in more than 2 inches. In the middle of these rocks live anaerobic denitrating bacteria that convert nitrates into nitrogen gas.
They also use deep sand beds which consist of a 5-6inch layer of sand that becomes anaerobic below the surface. Again the top layer of sand is aerobic but everything below an inch or two, (depending on how coarse the sand is) becomes anaerobic. The water slowly passes thru the rock or sand and the bacteria convert the nitrates.

I believe a similar thing could be achieved in freshwater using a sump (tank under the main tank) that is full of big pieces of porous rock. The water would pass thru this and eventually denitrating bacteria would become established and help keep the water clean.

The other way of removing nitrates is to grow plants. In marine tanks sumps are often used to grow macro algae that utilise vast amounts of nutrients. This limits the amount of nitrates that can build up. In freshwater tanks plants are often grown but it is usually only in the heavily planted tanks that we see a major reduction in nitrate levels. A sump could be used to grow plants in tanks that have vegetarian fishes or fishes that dig them up.
Many floating plants are superb at utilising nitrates. Duck weed and Azolla are considered a scourge by many aquarist but I love them both. They do an impressive job at removing nutrients from water. Water Hyacinth is one of the best plants for using nutrients.

 

[raptorrex]

colin, why do we not see any of these thing about. they look like they are a good bit of kit, doing a job most of us would love to to have done. question is why have they not become a part of our fish keeping gear? i know they are a bit costly to run, but not prohibitively so, and take up space. if they really do the job, why do we not see any and why could it not be found for sale, on the net, in the uk?

 

[Colin_T]

I think price is the main reason they aren't commonly seen. And most people don't know about them so they don't get ordered by any shops. I had to ask my wholesaler to get me one in and they didn't know what I was talking about. So I sent them the add I saw in the TFH mag and they ordered it in for me. Once their reps knew about them they started showing them around to different shops and they sold a few. But the price was the big factor. I mean why pay $400 for another filter that does the same thing as a water change.
I think Sera and the other companies stopped making them because they didn't sell enough.

 

[raptorrex]

I think price is the main reason they aren't commonly seen. And most people don't know about them so they don't get ordered by any shops. I had to ask my wholesaler to get me one in and they didn't know what I was talking about. So I sent them the add I saw in the TFH mag and they ordered it in for me. Once their reps knew about them they started showing them around to different shops and they sold a few. But the price was the big factor. I mean why pay $400 for another filter that does the same thing as a water change.
I think Sera and the other companies stopped making them because they didn't sell enough.

yeh and thats what worries me about them. if they really do hold the answer to high nitrates, as it seems, even considering the cost i would expect to see them all over. as a result the cost would tumble.
<a href="http/www.marinedepot.com/ps_ViewItem~Sea...;vendor=.html" target="_blank">http/www.marinedepot.com/ps_ViewItem~Sea...;vendor=.html</a>
seems someone still does them. this one seems to run on sulphur though. based on a calcium reactor, any chance of doing the same with another reactor?

 

[waterdrop]

LOL
Waterdrop's lead-up to this sounded like we were heading for the great debate

<...>

It takes a bit of noise to get the attention of the greats you see! OK, MAN, major enjoyment here!

1) T1 and bobo: Thanks for the Polishing advice (I've always thought those ADA competitors were primping for their pix, hehe)
I think we've confirmed that "ease of use" is behind T1's recommendation. I for one am going to remember my polishing lesson. Also interesting to imagine what the heck bobo means by a pico (tiny, obviously) filter... makes me dream up a picture of a filter designed like a fat ball point pen.. you hook in air at the top, hook it over the edge of the tank and every 48 hours you pull it up, unscrew the lower end of the cylinder part and restuff it with polyfloss or perhaps poly and carbon like bobo does.. oh well, just a daydream.

2) Colin! BRAVO! Tour de Force: I feel invited to the classroom to have the privilege of hearing an excellent professor (and hey, I should know as I spend my days walking the brick university paths) Many thanks for taking the time to type in that history and science lesson for us. That is absolutely an example of what I find fun about a good webforum.

Isn't it sad they felt they had to charge $400? Its almost impossible to find a good inventor and a good businessman in the same person/company. How clever of the Sera founder to dream up this drip pathway for anaerobic bacteria. Having it simplified down to a) a lot of surface area b) anaerobic bacteria and c) a carbon source plus water with nitrate sounds like it might have been quite clever too. They just lacked a good engineer and a contact in south china I guess Was this big rectangle on the inside or outside of your tank?

Also like how you think out loud about things like sumps with porous rocks - very interesting idea, maybe some experimenter in TFF will try it some day. Made me daydream about putting a big planted tank below a community tank and cycling water down and through the planted one and back up again kind of like a fresh water refugium that doubles as a display tank!

I assume the live rock and deep sand methods each have their own problems and hassles, right? Is the sand method not so efficient? It sounds like such a simple principle!

Your humble student, ~~waterdrop~~

 

[Colin_T]

<a href="http/www.marinedepot.com/ps_ViewItem~Sea...;vendor=.html" target="_blank">http/www.marinedepot.com/ps_ViewItem~Sea...;vendor=.html</a>
This one seems to run on sulphur though. Based on a calcium reactor, any chance of doing the same with another reactor?

I don't see why not. The only thing would be finding the Sulpha. I can't see many shops selling it for fear of it being used to make gunpowder. However the company might sell it seperately. I guess they will because they mention parts are replacable and the filter runs for several years before needing maintenance. The calcium in it is to simply bring the PH back up so the water passing thru doesn't drop the tank PH too much.
You could use an old calcium reactor and simply remove most of the calcium, replacing it with the sulpha. Or you could make it out of a length of PVC pipe or an old canister filter. Fill it up 3/4 with the Sulpha and put a fine sponge on top to stop it getting out of the filter. Then drip tank water into it and let the filtered water drip out the other end.
I used an Aquaclear powerhead to run mine. I made up a bit of black reticulation tubing in the shape of a Mr Lincon (the American president) hat. The Aquaclear pumped water into the tube. Then it went up and across before coming back down and into the tank. I stuck a tap in the top pipe and had a bit of airline coming off it into the denitrator. I used the tap to control the number of drips into the filter.

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Also like how you think out loud about things like sumps with porous rocks - very interesting idea, maybe some experimenter in TFF will try it some day. Made me daydream about putting a big planted tank below a community tank and cycling water down and through the planted one and back up again kind of like a fresh water refugium that doubles as a display tank!

I assume the live rock and deep sand methods each have their own problems and hassles, right? Is the sand method not so efficient? It sounds like such a simple principle!

Your idea of a freshwater refugium is spot on. Similar things are used in permaculture setups. Water from fish ponds is used to irrigate hyrdoponic crops and the return water goes back into the ponds. The plants use the nutrients leaving clean water for the fish.

The live rock seems to work pretty well, however I think the deep sand bed is not as effective. Simply from the standpoint that the water doesn't pass thru it readily. I know that is the whole idea, (slow water flow rates) but most of the water flows across the top aerobic layers and there is no way of forcing the water thru the anaerobic layers. It is assumed that the water naturally seeps into it, comes in contact with the denitrating bacteria, and then comes back out of the sand. The same thing happens with the rock but there is generally more water moving around the rock compared to the sand. The rock has more surface area to allow the water into it.
If they had the sand in a seperate compartment with a small amount of tank water slowly flowing thru it then it might work more efficiently. But if you did that you may as well use a block of fine filter foam and have that in a compartment with water slowly passing thru it.
The main drawback to the rock is it takes up space and displaces water from the system. Hence the reason for a sump, extra water. A coral tank can lose more than half its water volume to rock alone.
In a really big tank it's not such an issue but if the tank only holds 150litres and you lose half of that to rock, you don't have a lot of water left.

I think the best option for freshwater tanks would be a planted refugium. The water from the display tank slowly passes thru the planted sump and the plants strip out the nutrients. The refugium/ sump would also add water volume to the system allowing more fish to be held in the main tank. It could also be used as a spare tank to hold baby fish and if you had vegetarian fishes you could use the surplus plants from the sump to feed them.

This takes us back to the denitrating filters/ units, where the water is forced thru the anaerobic areas thus allowing for more efficient uptake of nitrates.