• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up
  • You can now follow UKAPS on Instagram.

Advice on flow rate

erwin123

Member
Joined
4 Mar 2021
Messages
1,069
Location
Singapore
The key is that flow is not the objective in itself, it is all about distribution/circulation and surface agitation as mentioned previously.
100% agree - no point having lot of water movement at the top but multiple 'dead spots' at the substrate level. This is especially a problem for 'tall tanks' where all the water flow is from outlets at the top of the tank.

Checking your flow at substrate level is pretty easy if you have an in-tank diffusor (another advantage of an in tank diffusor :cool:...) just place it at each corner of your tank at the substrate level and look at the CO2 bubbles, do they rise up more or less vertically and only start moving 'sideways' nearer the surface? Or do the bubbles start moving 'sideways' near the substrate.

when you see the bubble movement, you may understand why I am such a big fan of mini usb pumps (100litres/hr only) at the substrate level....😅

Of course, if you have a huge amount of flow, the risk of 'dead spots' decreases substantially.
 
Last edited:

james15

New Member
Thread starter
Joined
7 Sep 2019
Messages
13
Location
Derbyshire
I'll have a look at flow in the tank over the weekend. I think there is at least one dead spot. Just deciding what size wavemaker to go for. Unfortunately the manufacturer's guidance for what tank size they're suitable for is based on reef tanks which need much more flow, so if I went by that it would be way too powerful and my fish wouldn't be happy. But I'm thinking about 1500lph, based on what I've read in other threads here and elsewhere. I'm hoping that won't be too powerful. Please correct me if I'm wrong.
 

james15

New Member
Thread starter
Joined
7 Sep 2019
Messages
13
Location
Derbyshire
Update time!!

I've doubled the number of plants in there, and I've also replaced the faded plastic ornaments with real rocks for a more natural look (and they'll last much longer too!). The one on the right is still plastic, but being white to begin with you can't really tell it's faded and it still looks pretty good.

20220717_170216_copy_1600x900.jpg



Unfortunately I damaged the rhizome on the java fern while removing it from the pot. I'm hoping it will still survive since from what I've read they can successfully propagate from nearly nothing. But I'm prepared to replace it if I need to. I'm planning to get a few more plants later, but didn't want to get too many to start with as I can always get more if I need to. I'd definitely like to get some glossostigma in there.

Despite not being perfected yet, the existing plants are showing some signs that they are benefiting from the CO2 - in particular the Amazon sword which has been largely sitting there not doing much, has started producing a new leaf every couple of days. I've ordered a reactor, some plumbing fittings, and a wavemaker, so I can get to work on improving CO2 injection and flow. I disturbed some detritus when removing the old ornaments, revealing that there is indeed a dead spot on the left as I suspected.
 

james15

New Member
Thread starter
Joined
7 Sep 2019
Messages
13
Location
Derbyshire
Time for another update! I've now got a reactor and a lot more circulation. I started with a small wavemaker (Fluval CP2), and attempted to construct a bypass to run the reactor from the filter. Unfortunately I found that even with the bypass, the flow from the filter dropped off quite a bit, and also my reactor leaks a little bit (it is only a cheap one). The leak isn't bad enough to negatively affect the performance of the reactor, but enough to make a puddle in the cabinet so I opted instead to mount the reactor inside the tank and power it from a separate small pump (NewaJet 1200). The end result is very effective in terms of flow, and although it's early days yet the reactor seems to work well. Although the wavemaker is theoretically powerful enough to achieve sufficient flow combined with the filter, at least in terms of numbers, it would have been difficult to eliminate all deadspots. Now with the addition of a separate pump for the reactor in addition to the wavemaker, there are definitively no deadspots anywhere.

The reactor, pump and wavemaker are all located at the end furthest from the filter, and the reactor has an outlet located at the top (water flows in at the top, down the reactor column, then up through a pipe in the centre of the reactor and back out), to which I have added an adjustable duckbill nozzle, allowing me to direct flow towards the front of the tank and slightly upwards to create some surface agitation. Meanwhile the wavemaker is located further down to create a gentle flow in the lower part of the tank, back across towards the filter. The reactor does gurgle a bit and the flow is surprisingly powerful, so I have opted to run the pump on the same timer as the CO2 solenoid so it doesn't run 24/7. This way the noise isn't constant (not that it's unbearable anyway) and the fish get a bit of a break from the currents (though I have been careful to make sure there are always some areas where the current is always very gentle as gouramis in particular don't like it too strong, and in general the fish seem quite happy with the setup now). Meanwhile I still have an airstone running when the CO2 is off so surface agitation is maintained.

Having changed the setup I've got to experiment with the injection rate again but so far things look promising. I'm happy with the way the setup is working, and the plants are definitely showing the benefits. One of the new plants I bought a few weeks ago has already doubled in size, and the smaller echinodorus towards the front has started producing runners, something I've never seen it do in the three years that I've had it. The large plant at the back on the left (I can't remember what it's called!), which has been there since day 1, I have pruned quite heavily as the growth it had wasn't particularly healthy. Now with the proper setup it should have a chance do put on some healthy growth.

20220731_151022_copy_1600x900.jpg
 

james15

New Member
Thread starter
Joined
7 Sep 2019
Messages
13
Location
Derbyshire
Think it's about time for another update, things are going well! The plants have put on a huge amount of growth and are filling out nicely, and the echinodorus towards the front has now started flowering. The flowers however don't last long before getting eaten by my pearl gouramis! I've also planted a small glossostigma at the front, waiting to see how successful that will be. I have a suspicion my lighting may not be enough for it but decided to give it a go and see what happens.

20220904_162323_copy_1600x900.jpg
20220903_131139_copy_1600x1200.jpg
 
Top