General Questions
Sales partners in Germany
Question
Please call me a dealer for household and aquatic needs in the area of Bavaria or further.
Answer
We do not supply the dealers directly but rather via the wholesale trade or our sales partners. You can find our sales partners here. Please ask which dealer in your zip code area already carries our products.
Another option is the specialist mail-order business, which also supplies end customers. For example, you can order all ROWA products from Mrutzek Meeresaquaristik.
If you are interested in a system from the household sector, please contact us directly.
Where can I get spare parts?
Question
Where can I buy spare parts (membranes, etc.) for your osmosis systems in the Rhine-Main area (Frankfurt)?
Answer
Spare parts are available from your Aquaristik dealer. If your dealer does not have ROWA in stock, he can purchase the products from his wholesaler. You can find our sales partners here.
Another option is the specialist mail-order business, which also supplies end customers. For example, you can order all ROWA products from Mrutzek Meeresaquaristik.
Operating instructions 2-stage calcium reactor
Question
I got a calcium reactor for a seawater aquarium. The kalki comes from your house. My question is, do you have an instruction manual or a diagram of the CO2 and aquarium connection?
Answer
Here are the operating instructions for our two-stage calcium reactor.
Replacement filter cover
Question
MWSi Item No. 012611 silicate filter
I need a new replacement filter for the ROWAsystem filter module with special granules. Can I get it from you, and what does it cost?
Answer
Unfortunately, a direct reference is not possible for articles from the field of aquatic sciences. Please contact your dealer or the specialist mail-order company, e.g., Zoo Zajac (www.zoo-zajac.de).
Our products are distributed throughout Germany by Geisemann Aquaristic. The company Giesemann can call you and find a dealer in your area.
Reverse osmosis? What is this, anyway?
Answer
The ROWAsystem systems operate on the reverse osmosis principle.In reverse osmosis, the natural striving for balance is used.
If water of different salt concentrations is separated by an H2O-permeable membrane, a natural compensation takes place as water molecules penetrate the membrane and dilute the more saline solution. This creates a pressure difference, the so-called osmotic pressure. If a pressure far above the osmotic pressure is available, this process can be reversed (reverse osmosis).
In reverse osmosis, the water molecules penetrate the membrane from the saline side to the low-salt side. On the one hand, a concentrate is formed; on the other hand, desalinated water (permeate) is formed. The greater the pressure, the more sustainable this process is. The usual line pressure of 3–6 bars is sufficient for this and is the only energy that is needed.
However, so that the water on the concentrate side is not concentrated to such an extent that dissolved substances (e.g., calcium) precipitate and lie on the membrane in a blocking manner, the concentration must be controlled. This is done by the flushing valve, which in most cases is optimally adjusted with a ratio of four parts concentrate to one part permeate.
By occasionally opening the flushing valve completely, any substances deposited on the membrane are removed.