Having fitted the first of the Nexus 300 together with a Optimax 15000 pump I have noticed the bio chamber drops about 8 inches and the eazy chamber about 6. My first thought is that the pump is to powerful even though it was recommended.
Also with a Airtech 130 the K1 does not "bubble" all around the Bio chamber,I have checked the air pipe and it is clear.
Anyone have any suggestions or had similar problems ?
The Nexus is gravity fed from 4" BD
Regards
Mike.
Nexus 300 probs
Moderators: B.Scott, vippymini, Gazza, Manky Sanke
Re: Nexus 300 probs
Where did you get it from Mike?
Jules
Jules
Re: Nexus 300 probs
Hi Michael
Sorry but can we double check - RU saying that the differential between the level in the Easy and the pond is 6" when the pump is running?
If it is I would go a blockage of some sorts in the pipework or the drain cover is set too low.
I run Aquamax 15000 on my N200s via 4" drain and the head loss in the Easy is an inch, inch loss between easy and bio when easy is clean.
Regards
Dave
Sorry but can we double check - RU saying that the differential between the level in the Easy and the pond is 6" when the pump is running?
If it is I would go a blockage of some sorts in the pipework or the drain cover is set too low.
I run Aquamax 15000 on my N200s via 4" drain and the head loss in the Easy is an inch, inch loss between easy and bio when easy is clean.
Regards
Dave
Re: Nexus 300 probs
If your outer chamber (bio) is a lot lower than the inner chamber, and also the media is gathering around the exit plate , then you need to slow the flow down, It can take time to equal it out via valves etc.
If the media is not bubbling on the far side of the nexus it may not be on a level base.
How long has the nexus been running ? as another problem with the media turning over could just be that it still is not mature enough.
If the media is not bubbling on the far side of the nexus it may not be on a level base.
How long has the nexus been running ? as another problem with the media turning over could just be that it still is not mature enough.
Re: Nexus 300 probs
The only other explenation if it is a blockage would be either;-
A. Bottom drainb lid is too low.
B. You need to drop the inner chamber after cleaning and then take out your centre pipe from the Eazy and allow the outer chamber to backflush into the Eazy cleaning the "kisspoints" (these are the points where the centre chamber is moulded to the outer chamber allowing water to transfer from one chamber to another but no K1 to enter the inner chamber).
C. Once you have done this drain the outer chamber and reveal the "kisspoints" by moving the K1. Put the centre pipe back in and top up the Eazy. Once this is done take out the pipe and ensure and even flow through ALL the kisspoits around the filter.
D. Check that there are no blockages on the inlet to the Nexus.
Let us know how you get on.
Jules
A. Bottom drainb lid is too low.
B. You need to drop the inner chamber after cleaning and then take out your centre pipe from the Eazy and allow the outer chamber to backflush into the Eazy cleaning the "kisspoints" (these are the points where the centre chamber is moulded to the outer chamber allowing water to transfer from one chamber to another but no K1 to enter the inner chamber).
C. Once you have done this drain the outer chamber and reveal the "kisspoints" by moving the K1. Put the centre pipe back in and top up the Eazy. Once this is done take out the pipe and ensure and even flow through ALL the kisspoits around the filter.
D. Check that there are no blockages on the inlet to the Nexus.
Let us know how you get on.
Jules
Re: Nexus 300 probs
Hi guys,
i will try and answer all the queries :
This nexus has been running about six weeks ,it has 250 litres of K1 of which 150 litres has been in my old filters since K1 came on the market. The Nexus is definitely set level, have checked and checked for that.
DaveJ the differential are 6"and 8" from the top rim of the Nexus, the bottom drain cover has a good two inches clearance after spending several hours on the bottom experimenting I found this much clearance with the drain cover being driven again by a Airtech 130 thru' 1 " pipe attracted the most debris.
Jules I will try your suggestions tomorrow and post the results, prefer not to say publicly where I got it .
To my mind the air pipe does not appear to have a big enough diameter ,though I imagine thousands of others get on alright with it.Connecting it to a boot is a bit hit and miss !
The only thing I have possibly done different to others with this installation is that I ran 4" pipe from the nexus right to the inlet of the Optimax ! using the 4" fitting that comes with the pump.
Mike
i will try and answer all the queries :
This nexus has been running about six weeks ,it has 250 litres of K1 of which 150 litres has been in my old filters since K1 came on the market. The Nexus is definitely set level, have checked and checked for that.
DaveJ the differential are 6"and 8" from the top rim of the Nexus, the bottom drain cover has a good two inches clearance after spending several hours on the bottom experimenting I found this much clearance with the drain cover being driven again by a Airtech 130 thru' 1 " pipe attracted the most debris.
Jules I will try your suggestions tomorrow and post the results, prefer not to say publicly where I got it .
To my mind the air pipe does not appear to have a big enough diameter ,though I imagine thousands of others get on alright with it.Connecting it to a boot is a bit hit and miss !
The only thing I have possibly done different to others with this installation is that I ran 4" pipe from the nexus right to the inlet of the Optimax ! using the 4" fitting that comes with the pump.
Mike
Re: Nexus 300 probs
Hi Michael
When the pump is OFF and the water levels stabalised what is the level in the Nexus? - How much does it drop from this in the easy when you turn the pump on?
Did you glue the pipes in the BD after achieving 2" clearance of the cover?
Regards
Dave
When the pump is OFF and the water levels stabalised what is the level in the Nexus? - How much does it drop from this in the easy when you turn the pump on?
Did you glue the pipes in the BD after achieving 2" clearance of the cover?
Regards
Dave
Re: Nexus 300 probs
With 250 litres of K1 in the bio area of the Nexus , really you need an Airtech 150 , the 130 is only rated for upto 150 litres. This is probably why it is not turning well in the bio area.
Re: Nexus 300 probs
Hi again,
I have completed your suggestions:
With the pump off the water level returns to pond level almost instantly, with the level in the Nexus up the K1 Bubbles all the way around.
I have back flushed as Jules suggested,switched back on and the level drops to as was.
I am coming to the conclusion that either
1.Gravity fed 4" pipe back to the pump assists the pump to move the max amount it is capable of.
2.The pump is too powerful because of 1.
3.The Air pipe has insufficient diameter to pass max air to bio stage.
or
4.The connection to the Airtech boot is not compatible to delivering max air.
??????
Jules I have e-mailed you
I have completed your suggestions:
With the pump off the water level returns to pond level almost instantly, with the level in the Nexus up the K1 Bubbles all the way around.
I have back flushed as Jules suggested,switched back on and the level drops to as was.
I am coming to the conclusion that either
1.Gravity fed 4" pipe back to the pump assists the pump to move the max amount it is capable of.
2.The pump is too powerful because of 1.
3.The Air pipe has insufficient diameter to pass max air to bio stage.
or
4.The connection to the Airtech boot is not compatible to delivering max air.
??????
Jules I have e-mailed you
Re: Nexus 300 probs
Hi Michael,
Not sure that I am convinced.
Problem appears to lie with the big head loss in the easy, this is not something to do with the nexus it is simply that the incoming 4” pipe is struggling with the flow, hence the head loss.
4” incoming pipe should easily cope with 3000gph, but the head loss indicates it isn’t.
My starting point would be to double check that the domes haven't settled down on their stems. Pole with a suitable diameter stick at 90 degrees and you won't even get wet!!
Regards
Dave
Not sure that I am convinced.
Problem appears to lie with the big head loss in the easy, this is not something to do with the nexus it is simply that the incoming 4” pipe is struggling with the flow, hence the head loss.
4” incoming pipe should easily cope with 3000gph, but the head loss indicates it isn’t.
My starting point would be to double check that the domes haven't settled down on their stems. Pole with a suitable diameter stick at 90 degrees and you won't even get wet!!
Regards
Dave
Re: Nexus 300 probs
dave
Not sure what you mean by "My starting point would be to double check that the domes haven't settled down on their stems. Pole with a suitable diameter stick at 90 degrees and you won't even get wet!!"
Mike
Not sure what you mean by "My starting point would be to double check that the domes haven't settled down on their stems. Pole with a suitable diameter stick at 90 degrees and you won't even get wet!!"
Mike
Re: Nexus 300 probs
A shot in the dark here but take all the K1 out of the Eazy and the outer chamber and test the water levels do the same then.
Jules
Jules
Re: Nexus 300 probs
Hi Michael
Was thinking of a suitable implement you can slip under the dome covers to check the heights.
I had the exact same symptoms with head loss after changing the domes last year, after a while the domes settled on the stems and restricted the flow.
Regards
Dave
Was thinking of a suitable implement you can slip under the dome covers to check the heights.
I had the exact same symptoms with head loss after changing the domes last year, after a while the domes settled on the stems and restricted the flow.
Regards
Dave
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vippymini
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- Posts: 851
- Joined: Sun Sep 04, 2005 10:00 pm
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Re: Nexus 300 probs
how to check the gap.
make up a tapered gauge/ruler by cutting a tapered piece of plastic starting at 15mm a nd going up to 35mm, marking the important sizes on it with a waterproof marker pen. now tape it to your net handle. then slip out at night with a torch and insert the taper under the drain lid. then you can easily read off the gap under the lid..
why do it at night with a torch i hear you ask........ its easier to see the markings on the taper.. (plus itll give the neighbours a laugh)
make up a tapered gauge/ruler by cutting a tapered piece of plastic starting at 15mm a nd going up to 35mm, marking the important sizes on it with a waterproof marker pen. now tape it to your net handle. then slip out at night with a torch and insert the taper under the drain lid. then you can easily read off the gap under the lid..
why do it at night with a torch i hear you ask........ its easier to see the markings on the taper.. (plus itll give the neighbours a laugh)
Re: Nexus 300 probs
why do it at night with a torch i hear you ask........ its easier to see the markings on the taper.. (plus itll give the neighbours a laugh) 