Pond Filtration Ideas

[Lam Nguyen]

I am in the process of upgrading the filtration system of my outdoor pond and would like some ideas. It is a ~7,500 gal pond with two 3" Tetra BDs, two no niche skimmers, and two TPRs. The shape is oval and the dimensions are 21' L x 12' W x 5.5' D. I have two Nexus 300, one for each BD. These two Nexuses (?) will be pump fed by two Artesian PP 1/4HP. Each has a maximum FR of 4,100 gph, so after friction loss, I suspect that it will pump about 3,700 gph, which is the maximum FR that each Nexus 300 can handle. This will also give me a pond turnover rate of once an hour. The two Nexuses will be pump fed because they will be sitting above pond level and will gravity flow back either via a water fall or straight back to the pond. I will also max out on the K1 that these Nexus can handle. My goal is to grow about 7-10 koi.

The problem that I have and need help with is the two no niche skimmers. There are so many filtration ideas and I want to make sure that I design a circulation system that will complement the two Nexuses. I also want this circulation system to return back to the pond via the two TPRs to get some current. These are the options that I have so far:

1. No filtration needed. All I have to do is have a pump that pumps the water from the pond via the two no niche skimmers and return them directly back to the pond via the two TPRs. The rationale behind this is that there is already enough filtratin from the two Nexuses.

2. I already have a ~300 gal fiberglass chamber that I used as a mechanical vortex. I was thinking of having the two no niche skimmers gravity feed this vortex, fill the vortex up with a Jmat cartridge, and have a pump that will pump the water back to the pond via the two TPRs. However, my concern is the two no niche skimmers will not gravity feed fast enough since they only have 1.5" pipes and I want to pull about 3,000-4,000 gph.

3. Pump feed an Ultima II 4,000 from the two no niche skimmers and have it return via the two TPRs. I kinda like this idea.

4. Scratch the return via TPRs and pump feed two fiberglass filter boxes filled with either Jmats or Jbrushes and return via gravity. The only concern here is I really need current for the pond.

One more question for all you KB gurus out there: I am thinking of putting a couple of retrofit aerated BD domes in my two already-existing Tetra BDs. Do you guys think that this is necessary since the water returning from the two Nexuses will already be aerated? Any help is much appreciated. Thanks in advance, guys.

[gcuss]

Hi Lam,

Do you have a vortex/settlement before your 300s?

Grant

[gcuss]

For your skimmer circuit I would suggest possibly an easy pod. I've been really impressed with mine. Quite affordable, and they seem to be great at removing fines. My water cleared dramatically once I started running it. Cleaning is a breeze as well. I believe they handle up to 2500 GPH. The only problem I see is with the circulation you desire. I believe you're right about the 1 1/2 not being able to gravity feed any real flow, so you'll have to pump to the easy pods and then gravity flow back to the pond.

Perhaps if you aerate your bottom drains your circulation would improve from that, and you could get away with a gravity feed back to the pond from your skimmer circuit?

It would be real easy to add air to your drains.

Anyway, one solution.

Grant

[Flounder]

The best choice would be a sepatare skimmer circuit to the bead then back to the TPRs. Ofcourse an ABD is needed not only for the aeration but for sweeping the bottom more.

Btw the plural for nexus is nexi not nexuses.

[dick benbow]

koi is singular, koi is plural
koi is city, koi is rural.......( and the beni is epiderral )

[kent wallace]

I'm assuming that at this point the three inch bottom drains are direct suction to the pumps and then on to each Nexus unit. Is this accurate?
I have three inch adaptors that work well on a "No Nich" skimmer to allow a three inch gravity flow from them if necessary or are they already plumbed 1 1/2 inch through the pond wall?

[Lam Nguyen]

Originally Posted by gcuss

Hi Lam,

Do you have a vortex/settlement before your 300s?

Grant

Hi Grant, sorry it took me so long to respond....just got back from a short trip. No, I will not have a vortex/settlement chamber before my 300's. I think that the mechanical aspect of the 300's should be good enough to filter out the big particles before the water hits the biological chambers. Also, I will be dumping the mechanical chambers on a daily basis so hopefully this will be enough.

Do you or others use a vortex/settlement chamber before your guys' Nexus? Is it necessary to use a vortex/settlement chamber before the Nexus?

[Lam Nguyen]

Originally Posted by gcuss

For your skimmer circuit I would suggest possibly an easy pod. I've been really impressed with mine. Quite affordable, and they seem to be great at removing fines. My water cleared dramatically once I started running it. Cleaning is a breeze as well. I believe they handle up to 2500 GPH. The only problem I see is with the circulation you desire. I believe you're right about the 1 1/2 not being able to gravity feed any real flow, so you'll have to pump to the easy pods and then gravity flow back to the pond.

Hi Grant, yeah, I don't think that the 1.5" pipes will be enough to gravity feed enough flow to make an impact with my TPRs. I think that this why I am leaning towards an Ultima II 4,000 pressurized filter.

Perhaps if you aerate your bottom drains your circulation would improve from that, and you could get away with a gravity feed back to the pond from your skimmer circuit?

Grant, do you think that I need additional aeration by aerating the two BDs or can I get by with the aeration from the two Nexuses?

It would be real easy to add air to your drains.

Anyway, one solution.

Grant

Thanks Grant. Appreciate your input.

[Lam Nguyen]

Originally Posted by Flounder

The best choice would be a sepatare skimmer circuit to the bead then back to the TPRs. Ofcourse an ABD is needed not only for the aeration but for sweeping the bottom more.

Btw the plural for nexus is nexi not nexuses.

Yes, I am starting to think that an Ultima II bead filter might be the way to go. Thank you for your input and correcting my terminology.

[Lam Nguyen]

Originally Posted by kent wallace

I'm assuming that at this point the three inch bottom drains are direct suction to the pumps and then on to each Nexus unit. Is this accurate?
I have three inch adaptors that work well on a "No Nich" skimmer to allow a three inch gravity flow from them if necessary or are they already plumbed 1 1/2 inch through the pond wall?

Hi Kent, yes, the two 3" BDs are going to be direct suction to the pumps and then on to each Nexus unit. There won't be any vortex/settlement chambers before the Nexi. Do you think that this will be okay, or do you see any faults/problems with this set-up?

Unfortunately, the two no niche skimmers are already plumbed 1.5" through the pond wall, so there's really not much that I can do at this point. Do you have any suggestions on what I should do with these two no niche skimmers. Your input is much appreciated.