# N.V.N. Koi App > Koi hobbyist app for tracking fish, calculating needs, and logging treatments. (iPhone/iPad app by David Vonk.) - Source: https://appshunter.io/ios/app/nvn-koi-app/id1256688306 (this page in markdown: same URL + `.md`) - Developer: [David Vonk](https://appshunter.io/developer/1256688305) - Category: Utilities, Lifestyle - Price: Free - Rating: 3.70/5 from 6 App Store ratings · 3 written reviews indexed - Age rating: 4+ - Requires: iOS 11.0 · 21 MB - Languages: American English, Dutch, German (Germany) - Released: 2018-02-27 - Data updated: 2026-06-10 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/nvn-koi-app/id1256688306/reviews.md ## What is N.V.N. Koi App? This app is brought to you by the Nishikigoi Vereniging Nederland (N.V.N.) The first complete app for Koi hobbyists and professionals. In this app: Learn about the most common varieties with professional pictures. Keep track of your Koi and their length. After simple entry one can calculate a good indication of: -the amount of food your Koi need daily -how much filter material is minimally needed -use the desired bodyweight % you want to feed your Koi -or calculate the total amount of food a filter can handle daily The N.V.N. is the Dutch chapter of the Japanese Zen Nippon Airinkai (ZNA) and has knowledge sharing as its main goal to help its members to take care of their Koi as good as possible. In addition to this app, the N.V.N. offers courses, members receive the Koi magazine 6x a year, and members can call on the help of the Koi Pond Advisory Service. The N.V.N. prints six times a year, at least 132 pages of KOI magazine. By means of this magazine you can learn everything about the beautiful koihobby. With this magazine we strive to provide both the novice and the advanced hobbyist with the latest information. What we think is so important is that as a reader you no longer make the same costly mistakes that others have already made. In this magazine you can find all sorts of topics about pond construction, filters, fish diseases, experiences of members, news in the business, reports of (foreign) shows, Home made Ponds and needed materials and much more. As you will notice a large amount of information where you can successfully enjoy the hobby. The Dutch Koi Show, HKS, organized annually by the association, is the largest in the world in terms of size and number of visitors. The show therefore has a great international interest and is as such unique in the world. This show is also unrivalled in terms of atmosphere. If you download the free HKS app you are always assured of the latest info about and during this show. In this app: Keep track of your Koi and their length. After simple entry one can calculate a good indication of: -the amount of food your Koi need daily -how much filter material is minimally needed -use the desired bodyweight % you want to feed your Koi -or calculate the total amount of food a filter can handle daily It is also possible to keep track of all the water treatments through a pond log. Many more updates are planned. ## Key features - Track koi length - Calculate daily food needs - Calculate filter material needs - Log water treatments - View professional koi pictures ## Recent user reviews (3 of 3) All indexed reviews: https://appshunter.io/ios/app/nvn-koi-app/id1256688306/reviews.md ### 4/5 — Would be good to be able to add more details. *2021-10-30, version 2.11* My koi could include breeder and age. ### 4/5 — N.V.N. app *2020-10-01* Excellent app that allows importation of your fish. Informative and easy to use. ### 1/5 — Can I have my money back *2018-11-12, version 1.5* App is not good enough to release yet, very poor! ## Frequently asked questions about N.V.N. Koi App ### What is N.V.N. Koi App? N.V.N. Koi App is a utility application designed for koi enthusiasts. It helps users track their koi's length, calculate feeding requirements, determine necessary filter material, and log pond water treatments. The app also provides professional images of common koi varieties. ### How do I calculate food for my koi with N.V.N. Koi App? After entering simple information about your koi, the app allows you to calculate the amount of food your koi need daily. You can also specify a desired bodyweight percentage to feed your koi. ### Can N.V.N. Koi App help with filter management? Yes, the app can provide an indication of how much filter material is minimally needed for your pond. It can also calculate the total amount of food a filter can handle daily, aiding in pond maintenance. ### Does N.V.N. Koi App have ads? No, N.V.N. Koi App does not contain advertisements. It is a free application focused on providing utility features for koi hobbyists without interruption. ### What devices support N.V.N. Koi App? N.V.N. Koi App is supported on iPhone, iPad, and iPod devices. It is designed for Apple's iOS ecosystem. ### How often is N.V.N. Koi App updated? The latest version of N.V.N. Koi App is 2.11, last updated on April 11, 2021. The developer has indicated that many more updates are planned, suggesting ongoing development. ### What is the age rating for N.V.N. Koi App? N.V.N. Koi App has an age rating of 4+. This indicates it is suitable for children aged 4 and older, with no mature content. ### What is the user rating for N.V.N. Koi App? N.V.N. Koi App has an average rating of 3.7 stars based on 6 ratings. This suggests a generally positive but mixed user reception. ## Version history (last 5 releases) ### 2.11 — 2021-04-11 Added pictures for two Koi in Koi library Updated filter effectiveness values Added some filter materials Fixed spelling mistakes ### 2.10.2 — 2021-03-20 Added article: Filters 5 ### 2.10.1 — 2021-03-07 Added article: Filters 5 ### 2.10 — 2021-02-20 Added article: Filters 4 ### 2.9 — 2021-02-07 Added article: Filters 3 ## Apps similar to N.V.N. 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Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-10.*