Current & Water pressure

[Ivo Katrafilov]

Hi, from Bulgaria!

I'm interested what is more imortant for plecos, curent volume or water pressure. Is this equally (for the plecos) one powerhead 2000+ l/h and 2x1200 l/h, for example?


Best regards
Ivo

[Silurus]

By pressure, I guess you mean flow rate. This may vary for species, so what species in particular are you referring to?

[Ivo Katrafilov]

Sorry my English is verry poor. I put my question badly.

I have powerheads from 1100 l/h to 2600 l/h. They all have the same diameter of output. This mean that water from head 2400 l/h haveer higher velocity and exercise bigger presure on underwater objects in comparison with two smaler heads (1200 l/h), but they have the same flow rate.
Is this important, or only l/h is significant?


I have many Ancistrus spp. Hypancistrus spp. Peckoltia spp., Hemiancistrus subviridis, L204 and few long, slim Loricariids (Farlowella sp., Loricaria/Rineloricaria sp., Sturisoma sp.).

Best regards
Ivo

[Bas Pels]

Hi Ivo

Just as you wrote, if 2600 l/h goes through the same opening as 1200 l/h , the water will have to move faster. Flow rate is precisely that : average speed of the water

However 1* 2400 l/hr is the same as 2 * 1200 l/hr.

You are right, that the 2400 l/hr has a higher pressure than 2 * 1200, as pressure is speed * speed (speed square). Still, I never ever read anything about advantaged of high pressure. In fact, in 1 of my tanks, I devide the waterflow bovere it enters the tank. The current would otherwise flow the sand away

[shadowcat]

Hello Ivo and welcome!! Your catfish will generally appreciate a good amount of current. I use large capacity pumps in my tanks, from 2000lph to 4000lph, but I divide the returns through DIY spray bars. That way I can move a lot of water but the pressure at any one point is not too strong. It allows your fish to sit in the stronger current areas if they like and keeps a nice "average" current flow across a broader area. Best of luck to you and Bulgaria!!

[Mike_Noren]

The difference in pressure is probably of little consequence, especially as most fish avoid the narrow "beam" from high-pressure pumps. Presumably the important factors are dissolved oxygen content and water quality (nitrogenous waste & bacterial load especially).

[Ivo Katrafilov]

Thanks for the answer, they are very helpful. In my tanks, current/tank volume is 10/1-15/1.

Speaking for Water pressure, the water column is an important for breeding? I breed without problems my Ancistrus spp. and Loricariinae in aquariums with large bottom and 12'' high.

[apistomaster]

I like to use indirect flows if the pumps have high pressure/large flows. I have dealt with this in different ways.
1. The simplest way is to deflect the main flows off a side panel at an angle that redirects the now more diffuse flow in the general direction i want.
2. In my wet/dry filter return pipes I use slip fittings. Near the surface is a "Tee" and at the bottom I attach a 90* "Ell" Each outlet is adjustable for direction. Splitting the flow, top and bottom lessens the pressure and provides a wide latitude of directionality. A 2nd "Tee" could be added to the mid depth of the discharge pipe to further reduce pressure and provide even more flow direction control.

The depth of the water column would depend on the size of the fish. For small species like L134 or L260, I like 12 inches.
For long body Loricaridae like Sturisoma, I like 16 to 18 inches however, in the case of Sturisoma fry, I find they do better if kept in water only 8 inches deep until they are about 2 inches long.

2400 lph seems high to me. I only use one 600 lph power head in my 20 long to 40 gal breeder tanks.