Author Topic: Ok to Reduce the Filter Flow? (Read 16576 times) 16 replies

Wild Rover · « **on:** September 13, 2016, 12:18:02 AM »

Hi all

I'm running a Fluval Roma 200 with a Fluval 306 external filter. I have around 50 various Tetra's, namely Ornate, Serpae, Red Eye, Red Phantom and Diamond. Most are very young and I think the current is too much for Tetra's anyway. Fitting a spray bar looks very difficult so I was wondering, If I turn the flow down will I have enough filtration for this number of fish?

The calculator shows me at about 64% atm.

Thanks

ColinB · « **Reply #1 on:** September 13, 2016, 07:47:58 AM »

An almost impossible question to answer as there're so many variables. I would think the best method is to turn the flow down a bit, and then test the water every day for a week. If there's zero ammonia and nitriates, turn it down a bit more and keep testing. Repeat as necessary.

If your tank is 'mature' then there will be a lot of the needed bacteria on the substrate and decor, etc, and not just in the filter.

Sue · « **Reply #2 on:** September 13, 2016, 08:59:27 AM »

The often recommended filter flow is 5 times the tank volume per hour. It should give the flow rate somewhere in your filter literature. If it's not given in the manual, look it up on line. Fluvals are made by Hagen and their website contains a lot of info. But deduct some of the quoted water flow as Hagen is one of the companies that quote the flow rate of an empty filter. As soon as you add media, that figure drops.

There is a difference between enough filtration and water flow. Filtration is about having enough bacteria to 'eat' all the ammonia and nitrite; water flow is about moving the water through the tank in such a way that there are no dead spots where the water can get stagnant. It is possible to have sufficient filtration with quite a low water flow, and conversely, too much water flow with insufficient filtration. An example of the first would be the sponge filter in my betta's tank and the of the latter would be using just a power head with no filter media attached.

So I would do as Colin suggests, also watching for areas in the tank where there is no water movement.

Wild Rover · « **Reply #3 on:** September 13, 2016, 08:48:17 PM »

Thanks Colin and Sue, I will give that a try. It appears that the flow rate is 1150 litres per hour so allowing for the filter medium I guess it's about right at full power. I read elsewhere about people fitting coarse sponge or even pieces of stocking over the nozzle? Any thoughts on this?

fcmf · « **Reply #4 on:** September 13, 2016, 10:25:17 PM »

Hi Wild Rover,

I've used a piece of filter sponge in the nozzle of my filter, tied on with bendy wire. If you can get it to stay in place, that should do a good job. (In my case, it eventually came off but the fish seemed happy enough so I didn't bother re-positioning it although could easily have done so.)

Fiona · « **Reply #5 on:** September 14, 2016, 12:19:36 PM »

@Wild Rover I recently installed a spray bar to my Roma 200, I have a fluval 206 external filter and fitting it was really easy and I didn't even bother turning the filter off. I just pulled off the U shaped outlet vent and pushed the spray bar into the rubber seal and then connected it to the wall with the suckers provided with the spray bar. It took less than 5 minutes from start to finish. I also angled the spray bar so the holes are at about 2 o'clock, the water also hits the wall. It's greatly reduced the current and the threadfins are happier for it.

Wild Rover · « **Reply #6 on:** September 14, 2016, 01:01:26 PM »

Thanks fcmf and Fiona

@Fiona, I'm trying to visualise how you have the bar. is it along the back, along the side or vertical? Are the holes pointing towards the glass on which it is fitted? I presume it's under the water, is so is it angled up to create surface movement? Sorry for all the questions but I really like the idea of a spray bar, I have a Fluval kit but couldn't see a way to fit it, maybe I need a longer outlet hose. My inlet is bottom left at the back, and my outlet top right at the back, pointing to top left front.

Thanks for any advice. This sounds a loss less complicated in my head!

Littlefish · « **Reply #7 on:** September 14, 2016, 01:10:03 PM »

I have two Fluval Roma 200 tanks, each containing 3 mature axolotls, who get quite stressed with a high flow rate of water. I have a horizontal spray bars on my filters and I have them underwater and pointing upwards and towards the glass. This was how the keepers on the caudata forum I use suggested was a good way to have the filter because axolotls need a high rate of filtration (because they produce a lot of waste), but don't like a lot of water movement (it stresses them and their external gills curl).
My fellas have been in these, or similar setups for over 6 months and are comfortable in the low water flow created but pointing the spray bar towards the glass.

Wild Rover · « **Reply #8 on:** September 14, 2016, 01:46:05 PM »

Thanks Littlefish, much obliged

Is the spray bar along the back or the side and where is it in relation to your intake?

Littlefish · « **Reply #9 on:** September 14, 2016, 03:23:29 PM »

I have internal filters for my axolotls, so everything is together, with the spray bar (quite small) along the side.
When they get their new tank, much bigger so all 6 axolotls can go in together, they will have a fluval fx4 (currently sitting in the box, waiting for tank delivery). I plan to set this up much the same as the external in my dwarf puffer tank - intake at bottom right, outflow at top left, with the spray bar (quite long) horizontal along the back wall of the tank. With the axolotl tank the spray bar will still be underwater, and pointing slightly upwards and facing the back of the tank.

Wild Rover · « **Reply #10 on:** September 15, 2016, 11:55:09 AM »

Thanks all,

I have managed to fit the spray bar to the back. It runs virtually the whole length. I have it about 1.5 inches underwater, holes facing the front and angled upwards creating a nice ripple on the surface

@Littlefish Any particular reason you will face the back? I think the effect just looks nicer facing the front and it was a bit 'splashy' facing the back. I guess the current would be a little reduced bouncing off the wall but the little fella's seem happy enough now.

Sue · « **Reply #11 on:** September 15, 2016, 02:08:58 PM »

I have just read something on another forum. How to slow the speed of the water flow without affecting the turnover rate - drill more holes in the spray bar. The photo on the other forum shows several rows of holes down the length, and closer together than the holes in the original row.

Littlefish · « **Reply #12 on:** September 15, 2016, 07:07:02 PM »

More holes in the spray bar, that's a good idea.

I agree that the spray bar facing forwards looks better, as it does in my dwarf puffer tank. It will face the back in the axolotl tank because they have such a huge issue with water movement. Axolotls are much worse than fish when it comes to dealing with water movement, and it can be quite a problem, but they are so wierdly cute and have such goofy smiley faces, that people go to quite extreme lengths to provide suitable environments for them.

Fiona · « **Reply #13 on:** September 15, 2016, 07:35:32 PM »

Quote from: Wild Rover on September 14, 2016, 01:01:26 PM

@Fiona, I'm trying to visualise how you have the bar.

Mine is stuck to the back wall of the tank. I cut the hose too short so the spray bar is above the water. It's angled up and towards the wall and creates a gentle ripple across the water.

Wild Rover · « **Reply #14 on:** September 15, 2016, 07:39:14 PM »

Thanks again

I had seen others talking about making the holes bigger but tbh I don't think I need to. I'm really pleased with the effect and the fishy's are hanging out in every area of the tank looking very chilled

Littlefish · « **Reply #15 on:** September 15, 2016, 08:29:43 PM »

I think that the most important thing when it comes to water flow is whether or not the fish look comfortabe with their environment. It sounds like you've cracked it. Well done.

fcmf · « **Reply #16 on:** September 15, 2016, 08:47:55 PM »

Quote from: Wild Rover on September 15, 2016, 07:39:14 PM

Thanks again

I had seen others talking about making the holes bigger but tbh I don't think I need to. I'm really pleased with the effect and the fishy's are hanging out in every area of the tank looking very chilled

Great news.

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Ok To Reduce The Filter Flow?

Ok To Reduce The Filter Flow?

Author Topic: Ok to Reduce the Filter Flow? (Read 16576 times) 16 replies

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