Zeolites and bacteria – Experiences with the Zeovit Method – Part 2

Phosphate and natural nitrates values

During the initial stages a relevant decrease in nourishing substances can create some degree of apprehension. But natural nitrate and phosphate levels, measured in reef sea water, are equally very low. Fosså & Nilsen (1992) report 0.002 mg/l for nitrates, less than 0.015 mg/l for dissolved phosphates. The result of an in-aquarium measurement with two zeroes after comma does not have to mean that there are no nitrates or phosphates available, since the real cause of these results can be a natural concentration of these substances, one that renders common measurement techniques not effective. After a certain period of time, the zeolite mixture gets exhausted and it has to be renewed. Duration depends on the grade of organic pollution in the aquarium’s water. A period of 8 – 12 weeks can be deemed realistic. Choral tissue color may work as an indicator for substitution: if the faded tissue of SPS chorals becomes darker, the cause is to be attributed to a very elevated dosage of trace elements or in an increase of phosphate concentration or nitrates. If an increase of such values is excluded or if administration of oligoelements has not been increased, then it is possible that the zeolitic mixture may be exhausted and part of it must be replaced.


Size, Volume

220 x 80 x 60 cm ( L x D x H ), 1,056 l, plus filtering tank

Zeo2 1

Corals and other invertebrates

Anacropora forbesi, Acropora schmitti, A. formosa, A. solita­ry­en­sis, A. divaricata, A. corrida, A. abrsolhosensis, A. microphthalma, A. humilis, A. multiacuta, A. suharsonoi, A. prostrata, A. mille­po­ra, A. tenuis, A. locani, A. granulosa, A. jacquelineae, A. kirstyae, A. echinata, A. tenuis, Montipora capricornis, M. digitata, Cau­lastrea farcata, Blastomussa spp., Seriatopora hystrix, S. da­­micornis, Turbinaria renifornis, Stylophora pistillata, Porites at­ten­uata, Xenia umbelata, algae eating snails, Anaspida dactylomela, Lysmata ambionensis (2 x) Ste­nopus hispidus (3 x).

Fish species

Zebrasoma xanthurus (2 x), Thalassoma hardwickii, Ha­li­coe­res iridis (2 x), Pseudoanthias squamipinnis (6 x), Pseu­do­chro­­mis fridmani (4 x), Pseudochromis springeri (2 x), Chro­mis viridis (9 x).

Rock decorations

The rocky construction has been realized with 100 kg of freshly imported solid rock and structured in such a way to minimize support surface, in order to contrast sediment deposits.


UFO Classic ceiling featuring three HQI lamps (BLV, 10,000 Kelvin, 250 Watt) and two fluorescent blue tubes (Osram, color 67, 58 Watts). Lamps must be changed around every 8 months.

Water treatment

The external filtering tank, located in a separate local, has been linked to the aquarium using surface aspiration and water exchange between the main tank and the collection one amounts to circa 2,500 liters per hour. To the filtration tank an external countercurrent Sander skimmer (wooden diffusers, 4,000 l/h of air, 1,250 liters of passing water) is linked.

Water circulation

4 x Tunze-Turbelle ,,Electronic” with a yield of 4,000 liters each, managed by a Multicontroller featuring “pulsing” mode. Total water circulation per hour amounts to about 18.000 liters. To contrast sedimentation deposits, an always working tubation for further circulation has been added on the rear side of the tank.

Water Values

Measurement A (before employment of the ,,Zeovit” method):
Density: 1.024 (Aerometer)

pH: 8.4 – 8.5 (Digital measurement)

Calcium: 440 mg/l (TropicMarin)

Magnesium: 1,400 mg/l (TropicMarin)

Carbonate hardnes: 13° dH (TropicMarin)

Phosphates: 0.04 mg/l (Hanna Photometer)

Nitrates: 5 mg/l (Hanna Photometer)

Measurement B (after employment of the ,,Zeovit” method):

Density: 1.024 (Aerometer)

pH: 8.2 – 8.4 (Digital measurement)

Calcium: 420 mg/l (TropicMarin)

Magnesium: 1,350mg/l (TropicMarin)

Carbonate durability: 8-10° dH (TropicMarin)

Phosphates: 0.00 mg/l (Hanna Photometer)

Nitrates: 0.00 mg/l (Hanna Photometer)

Partial water change

5 percent every 14 days.

Addition of calcium, oligoelements etc.

Calcium reactor (Schuran JetStream 1) in continuous function, trace elements solution, strontium, iodine.

What is zeolite?

zeo2 2

Zeolite is made up by alkali containing aluminum silicate water, found inside the hollow spaces of volcanic alkaline rocks, particularly in basalt. Swedish baron Axel F. Cronsted, natural researcher and expert in mineralogy, discovered this substance in the 18th century and described it as a class of minerals. Baron Cronsted observed that this material, if warmed up, would start to boil. Therefore he called it “seething rock” (zeo = boiling and lithos = rock). Today it is known that zeolite is mostly made up of silicon, oxygen and other elements such as sodium and calcium, slightly bound like cations in a structure and in part exchanged with other cations. This way zeolite behaves like an ion exchanger. Employed in aquariums, zeolite removes useless nourishing substances from water under the form of ammonia (NH4). Because of its own composition, zeolite influences the water’s degree of harshness through an exchange of sodium, magnesium and calcium ions. For example, it absorbs chlorine, cesium, heavy metals and strontium and it absolves from many important buffer effects, stabilizing a determined pH value. In reef aquariology, use of this material is relatively new and the limits of its potential have not yet been fully stated. It seems like filtering with zeolite could remove nourishing substances from aquarium waters, sensibly improving living conditions for hard corals. It is of notable importance, however, to find some zeolite in the right composition, because not all the effects of this material are desired and useful in marine aquariology.

Advice for using the “Zeovit” method

  1. Avoid overdosing bacterial culture, nourishing solution as well as zeolite mixture.
  2. Be very careful about the zeolitic mixture effectively being crossed by current (2,000 l/h).
  3. Reduce dosing of oligoelements to about 20% of the advised dose.
  4. Reduce iodine dosage to a very limited level.
  5. Do not replace the zeolitic mixture in one take, just remove half of it with a two weeks delay.
  6. Do not employ alongside this method neither a UV sterilization, nor ozone, because both can be dangerous for added bacteria.

Do not use any material called “Zeolite”.

Part 1