Plz read and give me some advices

reason im not really worry about overstocked because im about to build a pond and goldfish and koi will be out there. but its pretty cold right now to make 1 so have to wait till spring or summer
By that time your fish will be stunted. I would try and rehome the gold fish and koi, then when you have a pond you can think about stocking it.
Your african brown knifefish will only grow to 8" (they are the smallest species of knifefish) and will be fine in your tank. The sharks will get too aggressive and you should only have one per tank, i would rehome them both as they will only cause problems when they get bigger.
 
i have a 36 gallon tank and im using Penguin 1140 Power head.The measured flow is somewhere around 300 GPH. is that too much for a liltle 36 gallon tank? im just a newb here.any help will be much appriciated

Why do you have a powerhead? Are you using an under gravel filter?
 
im using aqueon power 30 filter came with the kit.its not that good and im about to make a sump for the tank.i think i might as well use the power head as a return pump if the powerhead is not needed for just water circulation
 
a general rule of thumb for pumps operating inside a tank is 4-6 gallons per hour(gph) for water turnover. this means that for your 36 gallon tank you want a powerhead turning out 150-220 gph. the penguin 1140 pumps 300 gph, i believe.

i would consider another powerhead that gives around 180 gph.
eheim makes an aquaball powerhead that sells online for only 20 dollars plus 7 dollars to ship. that is one idea. maxi jet makes a pump in that range i gave you and so does aquaclear. aquaclear is my personal favorite and i would recommend them. the aquaclear 30 pumps 180 gph and can be found on ebay for 20 dollars with shipping.

hope that helps you.
 
thanks alot for the help.i have 1 liltle question that i need to ask,that if i ever make a 5 gallon sump can i still use the penguin 1140 powerhead for that lil sump ? or its still too much.if its still too much then imma go return it and get the aquaclear as u've recomended me.once again thanks alot for all the infos guys.really appreciated
 
I wouldn't put a sump on a tank that small. A good canister will have the same volume for filter media as a 5g sump and you won't need to drill your tank for a canister.
 
yes, you can make a sump for that tank. however, the trouble with the penguin powerheads is not the gph (gallons per hour) put out by the machine, its how high they can pump the water. as your sump will be below the tank, the powerhead would have to pump the water up that vertical distance, through the piping (vinyl or what have you) to your tank. so if you do decide to build a sump, you really should consider buying a regular water pump, as they can pump vertical distances much farther at the same gph versus a powerhead.

for more information, you may wish to read this article from aquariacentral.com ssiter site. it might be usefull to you:
http://www.monsterfishkeepers.com/forums/showthread.php?t=47105

hope that helps.
 
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