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Hydra 30 Internal filter

Discussion in 'Product Reviews' started by MasterofArts, Aug 29, 2015.

  1. MasterofArts

    MasterofArts Active Member

    Aug 3, 2015
    Likes Received:
    Where the street has no name
    United Kingdom United Kingdom

    I was chuffed and honoured when I was asked to review this new filter to which at the time would soon be hitting the UK market place, but here it is and in good time as a Christmas present for that hubby or friend in need of a filter and has somewhat a bit of geekness to them which is a good thing. :D

    Hydra 30 Internal Filter Review

    This looks and feels like a solid sturdy little filter at around 256mm in total height The width from back to front being about 114mm.

    For its size the filter itself boasts a flow rate of 500 - 550 l/h, consumes around 13 watts of power and the Hydra 30 that I am testing is marketed for tanks between 100 - 300l, with its big sister the Hydra 40 being suitable for tanks of 300 litres and above.

    The first area I looked at for observation was the supplied mechanical media (the bio foam).



    Mechanical Media sponge:


    There is no question that like all foam for filters it will remove the solid particles and over time house Nitrosomonas and Nitrobacter bacteria cultures, although I noticed the shape of the sponge its definitely not a standard foam fitting If we have good availability of spares this will not have any adverse affect on UK sales.

    I found this little filter easy to open for general maintenance and the instructions provided give clear steps of the workings for example "press to open" which was the instruction to open and remove the main casing from the motor housing and it did it with ease.

    For some reason I am more excited in testing this product the actual marketing concept on what it claims it can do and hopefully sets it a part from any other filter internal filter I have tested. The Hydro - Pure technology and a little Cata pure cartridge supplied is at the heart of this. In the Summer of 2013 I will be reviewing this Cata pure cartridge this will give me enough time to monitor various water stats and the effects during the ageing process with an approximate life span of 12 months.

    Cata pure Cartridge:


    In order to understand the technology that is said to be involved in this filter first we must look at and understand the oxidation process.

    Oxidation itself does not necessarily mean a reaction with oxygen containing compounds, it is rather the loss of electrons. However in the air and water oxidation does involve the reaction of a chemical species with an oxygen containing compound.

    The three most important oxidising species in the air are:

    the hydroxyl radical OH
    the nitrate radical NO3
    the ozone molecule O3

    It has been assumed with the term hydro being used, the technology involved will be basing its concept on the hydroxyl radical OH species.

    I agreed with a previous comment on the forum when this filter was first mentioned of being reviewed it was asked how sterile will this make your tank in other words... well hydroxyl radical (OH) is known to be the most important oxidation species out the 3 mentioned above. It is extremely reactive and able to oxidise most of the chemicals found and what is known as the troposphere, the unscientific explanation is simply the 'detergent of the atmosphere'.

    I done some research on what this type of oxidation would not have an affect on an my findings are: chlorofluorocarbons (CFC's), nitrous oxide (N2O) and carbon dioxide (CO2). The rate of methane (CH4) oxidation by OH is also known to be very very slow process.

    I am sure you can now understand why further study and a further review of the cartridge is required thiswill be completed as mentioned the summer of 2013.


    As you can see from the above picture, this is quite a powerful little filter, I have now had it in my tank for little over 3 months and it is still going strong. There is also a Venturi attachment meaning users of CO2 can connect up their supply directly to inject into the water flow where needed.

    Suckers/brackets - sturdier than I’d expected but just not strong enough, a rubber ‘bung’ at the foot of the unit means it’s upright and not angled but could be replaced with another sucker and it would still be level. I have noticed the filter keeps sliding down my tank simply meaning the suction cups are not enough for the weight of the unit but for a Gen 1 filter I am sure this be addressed in later models.

    I have not yet went to replace the impeller but here is a picture of its housing:

    impeller housing:


    Next is the actual power consumption, I have one of these British gas energy meters that record your current energy consumption and in such a tough economical climate that is hitting all industries purchasing products that consume less energy is not only better for our environment but also our pocket especially when energy suppliers continuously increase prices.

    When I switched the filter off from the mains, my meter dropped 13.9 watts of power although these meters are not 100% accurate it did give me a rough idea of the running cost which of course ultimately depends on your supplier.

    The main area I wanted to concentrate on was the impact on water statistics so before I put the filter into the main tank I done some water tests and took some samples:

    Water stats: 20/10/2012

    pH: 8.4

    gH: 16

    kH: 18

    NH3: 0

    NO2: 0

    NO3: 25 - 30

    The water testing method was completed in two different environments: "Water A", my main tank with normal statistics and "Water B", a high nutrient surface water tub I got from tesco's which contained excessive amounts of NH3 by using house hold ammonia and rotting prawns.

    By concentrating on ammonia in "water B" I noticed it does bypass the natural process of the Nitrogen Cycle by allowing NH3 to go straight to Nitrogen (N2) in one process. This resulted in what looked like the maturity of the tank within a 24 - 48 hour window with the end result in 0 Ammonia and Nitrite readings.

    As we all know Ammonia is a food source for nitrifying bacteria and is toxic to our fish, It is a key player in the Nitrogen Cycle and it is an important process, in my opinion it is a cycle that we should not look to bypass even with gadgets that claim to do so.

    I was hoping to do further testing on the bacterial colonation of filter media surface area and the filtered water by testing the nitrifying bacteria cultured to compare against another branded filter using these test kits:


    But at £70+vat for a pack of tests it was not cost effective at the time.

    With regards to Anaerobic Chamber the media used for this section is not included therefore I am unable to comment on the effect of any anaerobic processes, where dissolved oxygen is absent or only present in small quantities, although I wonder if such media is similar to Matrix and will hopefully be able to comment on this during the cata cartridge review in 2013.

    Lets now look at the end results of this little filter and see the impact on water statistics and organics.

    Water statistics: 01/12/2012

    pH: 8.4

    gH: 16

    kH: 18

    NH3: 0

    NO2: 0

    NO3: 15 - 20

    A strip test was completed after the first few days of installing where I noticed a fair drop in Nitrate (NO3) with a reading of just 5, but over the period of say 6 - 8 weeks with an average of 2 tests each week it slowly creeped up to 15 - 20 and maintained that level with no further increase really bar the odd spike after feeding. Even as I finish writing this article I still only have a level of 20.... to me this filter actually works under the environmental conditions of my tank but results could vary depending on individual bio levels and other filters installed. I think it is important to remember this is still only a filter like every other filter, it is designed to take a certain bio load.

    A water sample was taken this morning and there was a good difference from what was initially viewed under the microscope from the day 1. There was really only one type of algae diatom visible to me with no or very little muck visible. I presume some form of oxidation has taken place, the down fall may be when this filter is switched off as the muck/waste will build up again and if its to quick the bacteria may not be able to handle it and that is when problems may start similar to other oxidizors when you stop using them.

    With regards to the impact on pathogens at this time I am unable to test for due to no traceable cultures being available.

    Overall I have been fairly happy with the result of this little filter and with internals I always use the venturi not just for the added surface movement but this helps me identify when the filter is becoming clogged up and requires a wash. This filter compared with say the old Fluval 4 not only does the power head look to be a bit more powerful but it also doesn't clog up as quickly as our old trustworthy and reliable Fluval internal range, this could be because the organics and waste have been oxidized or just simply just an improvement in quality due to an extra mechanical & biological filter has been installed.

    Improvements well yes like everything there is always room to improve a product with the main concentration being on the suction cups at the back as previously mentioned. The question I am still asking myself is would I use it as just a stand alone filter or use it in conjunction with other filters and for a purpose only? I will only really be able to comment on this when my studies on this filter is complete in the summer of 2013 after the cata cartridge review so check back for updates.

    I would have liked to have seen an improvement in Oxygen but the problem I had when testing is that I was already at my maximum of how much oxygen my water can hold versus its temperature although there was no decrease.

    This filter wascurrently available from the sponsorat the time with a price of £49.95 which is a reasonable price for this filters capability.

    I hoped you enjoyed reading this review and be sure to let us know your finding as and when you get round to purchasing one of your own.

    All the best & merry christmas to you and your family,

    (edit: never got round to reviewing cartridge as I left the hobby for a while)

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