Is There Such A Thing As Too Much Current And Too Little Light?

[Aqua Andy]

Hello all,

My Juwel Lido 120 litre/ 32 US gallon tank was supplied with a 600 litre pump. As I was going to keep small Plecs, and I researched that they are fairly heavy waste producers, l purchased a 1000 litre pump and installed it when originally setting up the tank.

I've just started to wonder if the current produced by the pump is affecting the behavior of the fish?

I have aimed the pump exit towards the rear glass hoping to reduce the current. To try and give an indication of the current, it pushes some of the leaves of my plastic Amazon sword plants horizontal.

The Platies and Cories seem particularly shy/skittish and spend the majority of their time in a 10cm gap underneath the internal filter. The Cardinal Tetra and Endler seem to be behaving "normally". The Endler seems happy to swim at the top of the tank.

I'm going to re-home my Plecs so I no longer need to worry about high waste production. I'm thinking of purchasing the originally supplied 600 litre pump (I sold the one that came with the tank on ebay lol Doh!), and I'd like some opinions before I make my decision.

The tank light is only on in the evenings and during the weekend when I am viewing the fish. The tank receives a fair amount of natural light from a window. Could this be at all detrimental to the fish e.g. not enough or inconsistent light?

My water quality is perfect and the Amazon Sword plants provide them with a fair amount of cover. Are there any other factors which I haven't mentioned which could cause fish to appear nervous?

Thanks for reading my post,


Andy

 

[Nick16]

if the fish arent happy then you need to find the problem, do a W/C and then reduce the flow of the pump, if that does the trick then so be it, it sounds like it is a bit powerful, personally a pump like a Koralia nano will be sufficient in a tank of that size, i dot know if yours is more powerful than that?

what is the outlet of the pump like? is it wide open or like a tight narrow exit causing the water to blast one area?

 

[matchstickman47]

i turn the outlet against the galss so its less powerful

 

[Bebobb]

I would say that is a strong pump! I would have stuck with the 400l pump. D you still have the 400l pump? If so, I would move the media from the 600L to the 400L and use the 400L.

 

[Aqua Andy]

if the fish arent happy then you need to find the problem, do a W/C and then reduce the flow of the pump, if that does the trick then so be it, it sounds like it is a bit powerful, personally a pump like a Koralia nano will be sufficient in a tank of that size, i dot know if yours is more powerful than that?

what is the outlet of the pump like? is it wide open or like a tight narrow exit causing the water to blast one area?

Hi Nick,

Thanks for your reply.

That's why I posted my questions.

The water quality is fine.

I've read that reducing the flow of the pump is not good for it? How could I do this?

The outlet of the pump is narrow.


Andy

i turn the outlet against the galss so its less powerful

Hi Matchstickman,

Thanks for your reply.

I've already done this.


Andy

 

[Nick16]

is it an ajustable one?

if not you have 2 options, try to block some of the flow with decor like wood or buy a smaller pump and see the one you have.

 

[pippoodle]

I would say that is a strong pump! I would have stuck with the 400l pump. D you still have the 400l pump? If so, I would move the media from the 600L to the 400L and use the 400L.

why would you only want a 400lph pump on a 120 litre tank that turns the water over less than 4 times an hour

i always have at least 10x turnover in all my tanks as do many people - 400lph is a low turnover rate

make sure that there's nothing wrong with the Platies and Cories cos they enjoy fast flowing water

 

[Aqua Andy]

I would say that is a strong pump! I would have stuck with the 400l pump. D you still have the 400l pump? If so, I would move the media from the 600L to the 400L and use the 400L.

Hi Bettaboy,

Thanks for your reply.

The original pump was 600 litres and the current pump is 100 litres. I sold the original pump on ebay.

I think I'll try a less powerful pump. I just didn't want to buy one without researching first. I can't find any information about aquarium current/water flow.


Andy

 

[Nick16]

if you buy a koralia nano you will be fine on a 120L tank.

 

[Infidel_Uk]

I would say that is a strong pump! I would have stuck with the 400l pump. D you still have the 400l pump? If so, I would move the media from the 600L to the 400L and use the 400L.

why would you only want a 400lph pump on a 120 litre tank that turns the water over less than 4 times an hour

i always have at least 10x turnover in all my tanks as do many people - 400lph is a low turnover rate

make sure that there's nothing wrong with the Platies and Cories cos they enjoy fast flowing water

my LFS sold me a 500lph pump on a 177 litre tank , thats like THREE times an hour !

shocking

im fixing to collect a pump sunday that does 200 gallons an hour , so 8 times an hour should be ok for me ?

 

[Nick16]

well its not always about 10x an hours, becuase if you think about it a pump is doing nothing but moving the water around the tank (if you have a pump like a koralia, a powerhead type) it is not filtering anything and therefore it doesnt matter about 5x or 10x, that should only be applied to filtration.

and 10x is normally only used for highly planted tanks or those with messy fish to cope with the extra food lying around and to aid the flow of fertilisers all around the planted tank, oh and not to mention the food that does build up if you are keen on feeding, you cant siphon in a highly planted tank, imagine trying that in a dutch style tank

 

[Jaymz]

What would people recommend for a 190l corner tank? Currently I'm only at 4x turnover and want at least 10x for algae-reduction purposes, but don't want to stress the fish out. Koralia Nano? 1? 2? I also plan to change the external filter for one that's going to do 1000lph alone.