Max gph for new pump

[blue_martian]

Hi all,

Just wondering what your thoughts are on the max size of pump I should get for my tank. It's a 50 gallons and I'm planning on buying a new Hydor Koralia to assist with the circulation of the co2.

It's currently setup so the diffuser is in the corner and the length of the tank is 4 feet, I'm using a Hydor Koralia 1 placed underneath the diffuser to circulate the bubbles, it's rated at 400 gph but it doesn't seem to be as strong as I thought it would be. I'm sick of buying undersized pumps and I was thinking of buying the Hydor Koralia 3 rated at 850 gph.

Do you think this would be too strong for the tank? I'm planning on still using the HK 1 and placing it on the other end of the tank to really get the water moving.

Thanks for your tips

 

[Philosophos]

I've got my similarly sized tank planned to run an XP4 with a SCWD and two outtakes (eductors as a future upgrade) two viaaqua 480's and two koralia nanos on a wave timer. I believe the flow rate ends up being about 15x turnover or more. Either way, I find that multiple sources/directions of flow are a far better thing than just one or two.

 

[Biollante]

Hi,

If you are interested in an alternative, pm me.

Biollante

 

[csmith]

I believe the flow rate ends up being about 15x turnover or more.

How does everyone get away with this? Maybe I just don't get it, but how are your plants not lying on the substrate with that much flow? I'm trying to figure out what to do with my 55 and I'm hesitant to go above the nano and my fluval 350.

 

[LoudCreature]

We run average 18-20 times an hour.

some as high as 35 times.

LC

 

[Philosophos]

How does everyone get away with this? Maybe I just don't get it, but how are your plants not lying on the substrate with that much flow? I'm trying to figure out what to do with my 55 and I'm hesitant to go above the nano and my fluval 350.

Laminar flow, multiple sources and tinkering. I try to get some of the flow to oppose its self in order to create more complex patterns. The idea is to get everything moving in as many directions as possible to offer the best CO2 saturation possible, keep mulm off the leaves, break the boundary layer, and keep other column nutrients moving over the leaves. Your plants will respond by building stronger stems and (if your lighting and CO2 saturation is good) less lower leaf shed on taller stem plants.

 

[LoudCreature]

We tend to keep the flow in one direction think uphill to downhill

we also pulse

Biollante says think of a stream, river or even lake with even a lazy 1 knot flow

LC

 

[LoudCreature]

also generally try to avoid laminar flow

LC

 

[shoggoth43]

I've done the math a few times before but I recall 1 mph is somewhere on 18" per second. At 48" for your 50 gallon tank it takes less than 3 seconds to completely flush the tank end to end. 1 mph isn't that much velocity. 50x20 ( 3 seconds to flush the tank ) is 1000 gallons per minute x60 minutes gets you 60000 gallons per hour, or 1200x tank turnover per hour which is orders of magnitude greater than what is normally recommended. It's late and my math might be off but you get the idea here I think. It's not a question of how much flow you shove through the tank but rather HOW you do it.

Running a 1000 gpm pump with a 2" pipe is going to tear your tank apart. Dumping all that flow through a few nozzles into the tank will work better, especially if you use wider nozzles or eductor nozzles to spread out the flow. Prop type pumps and even an overhead manifold with multiple nozzles will get you where you want to be without flattening the plants and plastering your fish to the glass. RUGF plates and undergravel jets are other options although I don't recommend the RUGF plates as they can be a pain to deal with.

-
S

How does everyone get away with this? Maybe I just don't get it, but how are your plants not lying on the substrate with that much flow? I'm trying to figure out what to do with my 55 and I'm hesitant to go above the nano and my fluval 350.