What a bio sphere holder does
A holder keeps loose media in place and lets water pass through it. Maxspect Nano Tech bio spheres are loose media, and left to roll about in a sump they can drift into places you do not want them. A holder keeps them where you put them.
Ours is the Bio Sphere Holder and Pod Hotel V2, designed to hold 1kg of Maxspect Nano Tech bio spheres. The design allows good flow throughout the spheres, so water keeps moving through the media rather than around it.
It also does a second job. The space underneath is built to give microscopic crustaceans such as copepods and amphipods a safe place to multiply. Once a population is established, those crustaceans may feed on the bacteria and detritus living in the spheres above, so the holder and the media work as a pair.
It suits reef keepers who already run Maxspect Nano Tech media and want the space around it to earn its keep. If you do not own the media, the holder is not a reason to buy it.
Maxspect and Nano Tech are names of another company's products. This holder is an independent accessory designed and 3D printed by Marine Spec, and it is not made or endorsed by Maxspect.
Size and what it needs
Without the spheres loaded, the holder measures 83mm x 83mm x 191.5mm. That height is just under 20cm, which makes it the tallest of our 3 Maxspect holders and the only one built around spheres rather than blocks.
Measure before you order. In a sump, check the depth of the chamber you plan to use, because the media should sit under the water and the holder needs to stand clear of anything above it. A tall holder in a shallow chamber would break the surface, and media sitting in air does little. In a display tank, check the height against the rockwork and the water level.
Remember the spheres add their own bulk. The dimensions are for the holder alone, so allow for loaded media, and for room to lift it out when you want to rinse or inspect it.
The holder comes in 5 colours: Midnight Black, Scarlet Red, Aqua Green, Clown Orange and Regal Blue. A black and orange Special Edition also appears in our photos.
- Submerged
- Steady flow
- Secure
- Accessible
Sphere, block or anaerobic holder: which one
We make 3 holders, each for a different Maxspect Nano Tech medium. Pick the one that matches what you already own, since none is designed for other media. We have not published any other use, so check the dimensions before you try something different.
| Holder | Medium it takes | Size without media | Shape |
|---|---|---|---|
| Bio sphere holder | 1kg of bio spheres | 83mm x 83mm x 191.5mm | Tall and square |
| Bio block holder | 2 bio blocks | 109mm x 63mm x 36mm | Low and wide |
| Anaerobic block holder | 2 anaerobic blocks | Length 105mm, height 27.5mm; see product page for width | The slimmest of the 3 |
All 3 come in the same 5 colours and are V2 designs. The media is sold separately by Maxspect, and none of the holders includes it.
The footprints differ a lot. The sphere holder needs a deep chamber, while the 2 block holders stand 36mm and 27.5mm tall and suit shallower spots. If you run more than 1 medium, the table shows how much room each holder takes.
Placing it in a sump or display
We have not published a preferred position, so this is general guidance rather than a Marine Spec instruction. Keep the media submerged, keep a steady flow moving through it and make sure the holder cannot shift.
Steady flow means water that reaches every part of the media without hitting it hard. A holder sitting directly in front of a return nozzle takes the most force, and a toppled holder or scattered spheres can follow. A calmer spot in a chamber where water already travels is usually better.
Leave access. Media needs checking from time to time, and a holder wedged behind plumbing is easy to forget. In a display tank, choose a spot fish cannot easily reach into.
Check the position again after a day or so, and look at the flow with the pumps running. Use the dimensions from the table to see what fits, then build the layout around it.
Using it as a pod hotel
The hotel part sets this holder apart from a plain frame. It gives copepods and amphipods a sheltered space away from hungry fish and strong flow, while the media above carries on doing its job.
A hotel needs a starting population. If your tank has few pods, add some at lights out with the flow pumps off for 30 minutes and pour them in near the hotel and rock crevices. Our live marine copepods come in a 250ml pouch.
Look for pods with a torch after lights out, around the holder and on nearby glass.
Numbers that hold from week to week say more than a crowd on the first night. We cannot promise a population, because results vary with livestock and filtration.
Check the gaps now and then for a build up of detritus. Some debris is food for pods, but too much can clog the media and cut the flow the design is meant to allow.
Then feed them. Live phytoplankton gives the pods food directly, and the guides on copepod hotels and growing copepods explain how. The full set is on the pod hotels collection.
