Aquadyne vs Nexus - which to have next?

[miker036]

Hello to all,
Just joined this site after lurking around for a while - you guys know your stuff so;
I need your help please - I've had a pond for about 8 years and recently had to re-design and enlarge due to Koi out growing the old pond. I now have a much larger and deeper pond. Here's all the techie stuff that I know you all love.
At this point I will apologize the the length of this post.

New pond Horse shoe shape with covered area under deck remainder of pond in sun light most of the day. New pond has been up and running for 1 year
Approx 24 cu mtr of water
24,000 ltrs (5.333 Gals)
Water quality driven by:
Oase Biotec screenmatic 18 with a Bitron 55c UV pumped by a Oase Promax 2000 with satellite strainer
plus
Oase Filtoclear 15.000 powered by a Oase Aquamax Eco 16000 with satellite strainer
2 x Swim skims CWS
1 x Aquaoxy 2000.
Additional TMC Pond clear UV25 driven by a Oase pump.
Water readings
April No3 =25 No2 = 0 GH = 10 KH = 6 PH = 6.8
July same as above
Fish Register
4 x Sturgeon about 12"
3 x Large Koi about 15"
17 x small Koi between 6 to 9"
8 x Shubunkins
3 x small gold fish
2 x black fish (don't have a clue what these will grow into!)
Total 37 fish

The main trouble I am having is with suspended solids and murky water along with green algae and sludge on the bottom. The filters are clogging up and need complete cleaning every 2 weeks (and by cleaning I mean taking the filters out and washing them in pond water not just squeezing them in the box) Both the pump strainers also need to be cleaned out after about 3 weeks - I vacuum the bottom about once every 2 weeks.
By now some of you will have done some calculations, and yes your right, the total amount of filtering I have is not enough for the amount of water, My fault, I calculated the Bio mass on a pond stocked with gold fish not Koi!
The whole point of having this pond was to have a pond that has good water quality for my fish and so I can enjoy clean clear water So I need help.
I'm thinking of starting over with a new filtration system and would like something that I don't have to keep getting wet & too dirty when servicing the unit. My research to date has lead me to a bead filter or the Nexus 310 anybody got any ideas or suggestions please? As you will see from the photo's I've still got to install all the plants etc on the deck area and don't have any room to put another Biotec to make up the shortfall, also i really don't want to have another set of filters to clean
I'm based in south Bedfordshire if any one would like to visit . .
Thank you for reading this post and I look forward to your replies,(I hope).
Pictures of new pond x 4. please copy and paste (can't get the photos to download to this post)

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Thanks again,
Mike.
PS if I do replace the whole filter system I would be selling off most of the above equipment which I'm sure would prove to be a very good buy for someone.

[Jules]

Having experience of both Nexus and Bead systems I wouldn't hesitate recommending the Aquadyne range of filters. A sieve from the bottom drain and pump feed the filter where you have the ability to satelite the main filter anywhere you want to. You also get crystal clear water which Nexus units can struggle with.

Jules

[Brek]

Nice looking pond you got there, you will get many answers/opinions in reply to your question, bead filters seem to deliver the goods ref clarity, although are expensive to run, and some have reservations over channeling and build up of anerobic conditions if not fed by a sufficiently powerful pump as dirt can get trapped by the tightly packed beads and the inevitable 'channeling' will leave it there. I have no doubt as too the water quality provided by nexus filters, (I have an easy pod coping with 80 grams of food a day in a 6000L pond) but some are not happy with the clarity, they offer lower cost to run when gravity fed from a bottom drain, as just need a pump that will deliver the required turnover to get water back to the pond. So I guess when asking such questions it may help to say what your budget is to buy and run and also how much food you intend to drop into the water. Don't beat yourself up over the filters you bought as the figures quoted by those manufacturers are no help to anyone in planning the right amount of filtration for their fish, which at least EA try to do by quoting max feed rates not pond size which is pretty much useless (how can a given volume of water be relevant to the bio capability of a filter? it depends on the amount of ammonia being produced which is dependant on fish volume and feed rate) , many people recommend on your size of pond a sieve in front of whatever filter you do buy, which is then pumped to the filter, and as mentioned above running costs may influence your choice of bio filter, just my thoughts after completing my first year of Koi keeping.

[miker036]

Many thanks Jules & Brek for your replies,

Unfortunately in my quest for advice the replies inevitably posse even more questions.
May I get more advice please?
I'll take Jules 1st.
Hi Jules
Thanks for the heads up on the Aquadyne 1-0 to them at present (maybe I should start a poll)
When you talk about the 'bottom drain' do you mean (in my case)the Osae pump that sits on the bottom of the pond and drives my Biotec or is this an actual drain built into the bottom of the pond, I have a liner so can't alter the drainage layout now. If the Oase Pump is the 'Bottom drain' I take it that I would run this into a sieve to remove the solids then a new pump to pressurize the new filter unit - if this is the case how do you balance the flow of the new pump to work with the bottom drain pump that now feeds the sieve (is this making sense) so one doesn't bleed the other one dry.
I understand the remote access of the new filter, that makes good sense. Also is there any sense in putting a sand filter after the new filtration unit to take out any remaining algae etc? Oh god so many choices. I think I need someone to design a set up for me!

2nd - hi Brek
Thanks for your reply and comments on the pond - I have taken a lot of time re-designing & refurbishing both the deck and pond that's why I'm a bit annoyed with myself for not getting the right filtration plant installed, as an amateur I looked at the more advanced filters but assumed that they were for serious Koi keepers - not for the likes of me, I was mistaken and should have considered my fish a little more.

Very interesting and good point re; the amount of food given as opposed the the amount of water, I've not considered that before and makes prefect sense.
As regards to cost I worked out that my current set up uses about 625watts an hour (wattage taken from the hand books) then all added up together, say elec at 1.1 pence per hr per 100watts = about £600.00 a year.
My budget will have to be what it is to get this right - I don't know, say £2k-£2.5k. I would like to think I can reduce the running costs per year to about £400 - £500 pounds .
Feeding, now that a tricky one, As you know Sturgeon have to have a special protein rich food which, of course the Koi love so feeding is not easy.I have to feed the Koi first then put the Sturgeon food in and hope that they get to it before the others! I haven't weighed the food yet but will start today and post again tomorrow.
I know that ultimately I will need to choose a system but would really like others to have an input with design and type etc to give me a balanced view before spending out lots more dosh.
Thank you both for your posts,
Best wishes
Mike.

[eds]

Part of your problem with fines will be that the first thing that happens to the waste in your pond, before it gets to the filter, is that it gets mashed into bits by the pump! Is there any way you can dig out by the side of the pond and fit a 4" pipe through the side of the pond? This won't be as good as a normal bottom drain but you could more easily fit it through the liner using a flange fitting and then fit a 90 degree bend inside the pond to get the inlet down towards the base of the pond. This will take your pump(s) out of the pond and also mean waste gets into the filters fairly intact in larger pieces so it is easier for any filter to remove.

If you're going with a bead (or a shower which would be my choice as they get a load more air in them than the sealed box of a bead - but won't filter out fines either!) then I would put a sieve before as Jules suggested. If you fit the 4" gravity pipe then you can have that going into your sieve and then 1 pump to pump the water over the shower or the through the bead. If you go with the nexus then you could just fit that on the 4" pipe and then pump back to the pond.

The final thing is do you have a skimmer on the pond? If so you could always fit another pump and a bead on this line so you have a nexus on the 4" pipe and a bead on the skimmer line.

[dannyboy]

Hi,
I would say with no bottom drain that you are deffo going to need a bead filter, i have 2x 4.4 aquadyne's and clarity if brilliant.
I would say on your size of pond you could have a 2.2 with a 1/3 Artesian pump which runs about 330 watts
Have a look at Koi waterlife's web site
http://www.koi-waterlife-centre.com/kwlcshop/" onclick="window.open(this.href);return false;
Fines not a problem with an aquadyne
Hope that helped


[img]http://i222.photobucket.com/albums/dd92 ... ish099.jpg[/img

[miker036]

Hi Eds & dannyboy,
Thanks for your posts - I am changing internet providers at the moment and will reply about the middle of next week when back up and running, (using a Dongle at the moment , it takes ages to get anything to load) so please bear with me. Am taking all on board and will give an update soon.
Thanks to all for posting, please feel free to add any further info or thoughts, I really do appreciate all the input and views.

Looking forward to looking at all dannyboys Photo's - the picture in the post is fab.

Any one got any thoughts on installing Vacuum bottom drains?

Best to all
Mike.