Water Circulation In A Planted Aquarium

This is something that I discuss with customers time and time again but in all honesty a lot of hobbyists don’t realise how important it really is. Water circulation in a planted aquarium is really important.

Picture this – your aquarium is heavily planted, you infuse CO2, add excellent fertilisers like AE Design Aqua Nourish and Aqua Nourish+. You have good lighting and perform regular large water changes but…you only have one filter pushing around the water, CO2 and fertilisers. And for some reason you have algae – anyone been in this situation?

The reason you have algae is insufficient water distribution. Whilst you get full marks for everything else, in a planted tank that is CO2 infused, you have to get everything right otherwise, algae grows. If you only have one filter pushing water around and you probably have wood/rocks so there will be quite a few dead spots or certainly areas that don’t get much if any water flow due to the deflection they cause. Water flow is the life blood of the system – it carries nutrients and CO2 to the plants and if circulation isn’t up to scrath, your plants don’t get what they need and algae responds. When diffusing CO2 into your tank, you literally have to see the bubbles everywhere and if they’re not in every nook and cranny, you can bet the plants will be struggling in that area.

Water circulation pumps don’t need to be particularly large, in fact some are quite small and powerful. Let me introduce you to Hydor Pico Evo Mag 650. This amazing tiny piece of equipment moves 650L of water per hour and it’s only 4.5x3x6cm which means that it can sit in your tank and barely takes up any space. It contains a magnetic suction cup so you place it anywhere and the idea is to direct it towards the areas in your tank, which don’t get enough water movement. If you have foreground plants, you would need to direct this onto them – in fact this is one reason so many struggle with them. Because they are at the bottom of the tank, they don’t get much water movement and therefore not much CO2 and fertilisers. By pointing a Hydor Pico Evo Mag 650 towards them, it will push the necessary water, fertilsers and CO2 onto your foreground plants forcing them to sway in the current (perfect!).

Ensuring you get your water movement just right, removes so much stress from your planted aquarium. If you want to see our other range of water circulating pumps then visit this link here.

If you are having problems with your aquarium, why not ask a question on this blog and I will respond.

In addition I have managed to find an excellent image of a larger planted aquarium in which world class aquascaper Mark Evans demonstrates perfectly why a circulation pump is required.

20 thoughts on “Water Circulation In A Planted Aquarium”

  1. Hi
    I am thinking of buying a pico evo mag 650 for my 125 ltr tank,do you think this would be an asset and also the right size or would i need a bigger one ? also would you position it to be in the same direction as the filter out flow ?
    I have no co2 in this tank and i am using easycarbo and profito ferts,at this time the tank is not that heavily planted at the moment but i do plan to ad more plants in the future.
    David Collins

    1. Hi David

      The pico evo mag 650 is an excellent small circulation pump and would definitely be an asset to your aquarium – even in non CO2 tank like yours, circulation is really important 🙂

      Positioning is totally dependent on your set up – for example you may have wood or rocks that block the main flow of water. A good test to see where your dead spots are is sprinkle some fish food into your tank and watch where the flakes go. You’ll soon see where water flow is less than ideal, then position the pico in that direction.

      Let me know how you get on.


  2. Hi, I have a 200 litre tank (although only about 170litres of water given hardscaping and substrate etc) I have an Eheim 2217 filter running with spray bar at one end, uplift at the other end of the tank. Would the EvoMag 650 be big enough to add to the tank or should I really go for something a little bigger (in term of L/Hr)?

  3. I have recently purchased the Koralia 900lh circulation pump for my Trigon 190litre corner tank. The internal filter/pump housing Is located at the rear of the tank (corner) where would you recommend placing the circulation pump ?

  4. Hi – I have a 240l Ferplast tank with some initial planting (slowly getting to grips with what works) and pressurised CO2 & Eheim Professional 3 external filter feeding a spray bar across the top of one end (inlet bottom/other end).

    Would a Koralia 1600 be too much?


  5. Hi, Should the circulation pump be run 24/7 or is it adequate to run it during the plants photoperiod only ?.


  6. Hi I have a vision 450 l ,fx6 filter with inline co2, hoping to order my plants soon to create a heavily planted discus tank , which koralia would you recommend for such a large tank or would I be better with two koralia

  7. Hi, I have the juwel rekord 700 tank which is about 70+ litres. It’s heavily planted and the light I have is the fluval fresh & plant 2.0 32w which is on for 6 hours a day. I dose macro and micro on alternate days and dose liquid carbon daily. Now I’m struggling a bit with algae on my plants and this pump could be the missing link. Will this be too powerful for my size of tank? Is the smaller capacity ones? I don’t want it to upset my apistogramma panduro pair.

    1. Hard to tell if it’s too powerful – sometimes it’s case of trying and seeing what happens

      If you are concerned though, the smaller pump would probably be better.

  8. Hello I found your site and I’m wondering if you can advise. I have a 200l 110x50x45 and a aquamantra efx 300 a JBL CristalProfi e901 and also a hydor koralia evolution 5200. I’m thinking it’s going to be better to have 2 small circulators and 1 filter as the koralia I have seems too big in my tank.
    Can you recommend what would be best? Thank you

  9. Hi. I am setting up a 30 gal tank with a relatively high flow rate–350 gph from a HOB filter. The tank is square in shape. Just wondering if there are particular plants you would or would not recommend for such a set-up. Lighting is moderate; no CO2. Thank you.

  10. Loved your blog. It’s really helpful for me to run my hobby. So, will you share more information please? I will be really happy if you visit my blog too, for my experiences.

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