Sump filtration

[Malc-C]

Hi,

I'm currently using an Ehime Ecco 2233 (3 compartment) external filter to maintain the filtration of my 100 ltr (net) tank. The tap water here in Hertfordshire (uk) comes out of the tap with a Nitrate level of 40ppm (actual water board stats report it at 38ppm), so I was looking at making some form of sump filter similar to those used by the marine guys.

Obviously I wouldn't need a protien skimmer etc, but would like to incorportate some form of wet and dry filtration to lower the nitrate. It would also need to have some form of water extraction that doesn't involve drilling the tank as that is becomming established.

I'm also on a tight budget, so would be looking at either getting glass / perspex cut and siliconing it together myself, or using "off the shelf" things like a small tank.

Cheers

Malcolm

 

[Def]

Hm.. I don't see a question in your post

Sumps are easy to do. If you don't want to drill then you'll need to add a pump a few inches below the waterline in your main tank to pump water over the rim and down a standpipe into your sump. A return pump in the sump feeds it back up into the tank. Set the sump up however you want...

 

[smithrc]

right... I've got the answer drawn up in ruff already

a syphon overflow box that you attach to the side of a tank... It works in my head - I'll dig out my computer sketch...

 

[smithrc]

found it from a previous post...

You will need one return pump from the sump for this...
The syphon 'link' will keep the water level in the fisrt stage at the same level as the tank. the water will overflow into the 2nd chamber as the main tank level rises. This water will then be routed through the bottom of the overflow chamber into the sump.

the return pump will then return the water to the main tank.

If the pump fails - the cycle will stop - with no risk of flooding.

 

[smithrc]

Hm.. I don't see a question in your post

Sumps are easy to do. If you don't want to drill then you'll need to add a pump a few inches below the waterline in your main tank to pump water over the rim and down a standpipe into your sump. A return pump in the sump feeds it back up into the tank. Set the sump up however you want...

[snapback]883595[/snapback]​

Just pumping wont work...

if the return pump fails the upper pump will pump as much water as it can into the sump and possible flood.... then it will run dry and it too will die...

If the upper pump fails the sump will be pumped dry - overflowing the main tank and the pump will run dry and die.

If they run at different rates - see above.

 

[Def]

Just pumping wont work... if the return pump fails the upper pump will pump as much water as it can into the sump and possible flood.... then it will run dry and it too will die...

That's why you place the input pump a few inches below the surface only, ensuring that the max volume pumped from the main tank won't flood the sump. Add an auto-shutoff to the pump to stop it running when dry.

If the upper pump fails the sump will be pumped dry - overflowing the main tank and the pump will run dry and die.

Again, it's why you need an auto-shutoff.

The problem with overflows as per your diagram is that they lose siphon if the water level falls. Even in your design the return pump in the sump can fail, which would cause water to siphon into the overflow and down into the sump (potentially causing a flood, thus the position of the intake for the overflow pipe is as important as the position of the pump I recommended). Water will continue to siphon until the level in the tank drops below the siphon intake, in which case the siphon will break and have to be manually restarted.

*edit* I'm clearly retarded because bbcode is beyond me.

 

[smithrc]

The problem with overflows as per your diagram is that they lose siphon if the water level falls. Even in your design the return pump in the sump can fail, which would cause water to siphon into the overflow and down into the sump (potentially causing a flood, thus the position of the intake for the overflow pipe is as important as the position of the pump I recommended). Water will continue to siphon until the level in the tank drops below the siphon intake, in which case the siphon will break and have to be manually restarted.

[snapback]883623[/snapback]​

Thats where ht over flow part comes into play. The overflow section it what controls the water level. you position the 'device' in such a position that the divider between the 2 sections is just below the desired water line.

The syphon will maintain the levels between the tank and compartment 1.
If no water is being pumped into the tank the water level wont rise and the water will now go over the divider = no flood

 

[Def]

Thats where ht over flow part comes into play. The overflow section it what controls the water level. you position the 'device' in such a position that the divider between the 2 sections is just below the desired water line.

I think there's some confusion here. For the siphon to operate, the "input" side has to be "higher" than the output side. Try it yourself - get a plastic hose, stick one end in your tank at, say, 3 feet off the ground. Start the siphon and stick the other end in a bucket a few inches off the ground. Basic waterchange/water siphon principles, the water flows from the high end to the low end. Now raise the low (bucket) end up to the same level or above the high (tank) end - the siphon doesn't break, but it doesn't siphon because the water has found its level.

The divider between the 2 sections can be wherever you want it to be. The input side of the pipe MUST be above the output side of the pipe (the side in the overflow box). And therefore the siphon will continue until the water level drops below the input and the siphon breaks. It has nothing to do with the position of the divider in the overflow box. You can put the overflow box on the ground if you like, the same thing happens.

If no water is being pumped into the tank the water level wont rise and the water will now go over the divider = no flood

As above, water will siphon into the overflow as long as the seal is maintained. If you have your siphon input at the bottom of the tank (stupid, yes, but the principle...) then the entire tank will siphon into the sump...

Unless I'm utterly misunderstanding what you're trying to say....

 

[Malc-C]

Hm.. I don't see a question in your post

The question was in the sub-heading

Some interesting discussion on the priciples of syphoning. I don't thing having two pumps is a viable option, as even without pump failure you would have to have two pumps with exactly the same flow rate so as not to have problems with under / over flow.

Assuming the overflow / return system can be made to work without issues, how many "compartments" should the sump filter have to provide adequite filtration, and hopefully reduce Nitrates.

Lastly, do sump filters work any better than normal external filters ??

Cheers

Malcolm

 

[Malc-C]

Found a link on a different forum with some really cool info

Here have a look !

I like the look of this design for the syphon device - comments please

 

[Malc-C]

How difficult would it be to make something like this:

I'm mainly concerned with the overflow skimmer, and the other item is just a box which should be simple enough for my limited skills

 

[andywg]

Just a quick point or two:

1. Sumps do not lower nitrates. The reason marine systems remove nitrates is because of the anaerobic zones in live rock and the ammonia uptake of macroalgae. You could utilise a freshwater algal turf scrubber though these are not very common yet. (And noisy).

2. Nitrates of 40ppm isn't that bad. You can still keep stingrays with that and they are one of the more nitrate sensitive species.

3. I myself would never trust a syphon overflow. Supposing a fish or snail gets in the tube and blocks it. You end up with a dry sump and probably overflown tank. Or if it loses syphon, again, catastrophe.

All 3 of my sump systems are drilled and it works fantastically, and with a durso standpipe they are near on silent. Drilling is nowhere near as hard as some would have you believe.

You never use a pump down and a pump back. Pumps never work at the stated amount and you only need a slight imbalance for it to go horribley wrong. Remember, when you are doing a sump, you really need to plan for the worst. An auto-shut off can, and will, break, and always when you are at work or on holiday.

Another point to remember is you have to work twice as hard for CO2 levels if you plan on plants.

Basically, if you want to do a sump, do it well, and that means drilling the tank. You don't have to drill the bottom, you can drill higher up and put in a mini-weir (excellently shown in Paul_MTS's thread in the marine forum about his nano-reef).

HIH

Andy

 

[Malc-C]

Thanks for the info, I was always under the impression that it was the airobic bacteria that formed in trickle filters that reduced nitrate... thank for correcting me.

Given the tank is already well established, and I use a fermentation CO2 system, a sump filter is not the ideal way to go for a freshwater set up.

Cheers guys

Malcolm