Facelift for an old skimmer - need creative mod ideas

[fbacungan]

Hi Fellow Reefers,

I have an old downdraft skimmer (Predator PDFS II) that I'm looking to modify. I would love your input to make it more efficient.

In order for the skimmer to work properly in its current state, I need a pump that pushes a ton of water in it to make a small amount of bubbles.

Tank size: 140 gallons with 45 gallon sump
Sump will not be in the sump and will stand in its current state at about 36" outside the tank

Pump: Rio 2100 (2600 Lph/686 gallon/hr), looking to mesh mod it

My questions are:

1 - I'm thinking of drilling the base to fit the new pump externally, but not sure how or where

2 - I'm thinking the water input can be the same, which is at the top. I'm also thinking of using gravity to feed the skimmer, but I read that's not really the best way. If not, what's the best way and how much should be pumped through it?

Any creative ideas to bring this old school skimmer to the modern age would be gladly welcomed!!

 

[iroll253]

That looks like an in sump skimmer only. I cant see where the pump intake is on it. I would use a way bigger pump especially if its going to be that far from the tank.

 

[Skimmy]

that skimmer is a POS, design -wise.

i would ditch the whole injector in the lid and look at retrofitting a recirc pinwheel pump on the skimmer body or black box (opposite end from the outlet) or cutting a hole in the bottom to fit a pump in there.

the body looks really skinny , what are the dim's of this skimmer?
the things it has going for it is the wide neck, and it's tall.

 

[Skimmy]

also, the rio pump??
....utterly useless for your skimmer needs.

and forget about feeding from the drain, too unstabe, and unable to dial in exact dwell time of water, not enough benifit to merrit doing.

so, im thinking a sicce psk 2500 will fit in the bottom of that black box, you might be able to squirrel one down the throat of the skimmer.
the real question is if the skimmer body is too tall, producing too much back pressure to efficently feed air to the sicce.

the other (easiest)option is to cut 1 hole for the pump to feed into the skimmer body. then you just pop in a uniseal and attach the pump kinda like this:
http://www.premiumaquatics.com/Merc...Product_Code=ES-PSK-100&Category_Code=es-skim

you could of coarse cut 2 holes and make it a recirc pump. you could do this with the sicce as long as it was submerged.

also, I bet you could find a used sicce pump for cheap and rebuild it with a new pinwheel and volute/venturi, as long as the motor was still good.

 

[fbacungan]

Thanks for the replies.

Mark, your answers (and some follow up questions) below.

>the body looks really skinny , what are the dim's of this skimmer?
>the things it has going for it is the wide neck, and it's tall

The dimensions are 36 inches high, and 4.5 inches in diameter. See picture. The middle part can also be removed, which is about 12 inches. The base is a 12 inches long by 8 inches wide by 4.5 inches tall.

>also, the rio pump?? ....utterly useless for your skimmer needs.
Awww. Shucks.... I thought I could use an extra pump that was lying around and save some bucks. I looked on the web for the sicce psk 2500 and the dimensions are such that it won't fit down the 4.5 inch tub.

It looks like both of your options are for the skimmer to be placed in a sump. My sump is in the cabinet which a clearance height of about 25 inches. Even with the middle piece out, it won't fit. So I am looking at an option where it can be placed behind the aquarium and plumbed into the sump.

>and forget about feeding from the drain, too unstabe, and unable to dial in exact dwell time of water, not enough benifit to merrit doing.

So, assuming this will not be in the sump, it looks like I'll have to drill a hole for an input tube and ditch the output for something bigger? How much flow must run through this puppy?

>you could of coarse cut 2 holes and make it a recirc pump. you could do this with the sicce as long as it was submerged.

Couldn't I still make it a recirc pump even if not submerged? I know the danger of an external sump flooding my living room.

Lastly, what other external pumps (other than the sicce) would you suggest?

 

[Skimmy]

wow, 4.5 x 36...wtf were these people thinking?? ...lol

i can see that the very bottom of the skimmer has an inner sleeve to accomodate some plumbing from the injector that is not pictured, so yeah, that kinda changes things...

so, as you mentioned, you can keep it an external skimmer and use a different pump for recirc. im thinking maybe a eheim or an ocean runner...
but that 4.5 x36 is a killer...

the other thing you might consider is to replace the injector with a modified beckett injector (theres a couple of threads about it on RC in DIY) that would require less than the regularly prescribed 1800-2000gph to run a beckett injector properly.

and do you have a pic of the middle pumbing piece? is it filled with bio-balls normally?

 

[Skimmy]

....or you could go uber old school with a new twist:
fine pore ceramic air diffusors and and a nice powerful air pump.

http://www.aquaticeco.com/subcategories/3533/Sweetwater-Air-Diffusers
http://www.aquaticeco.com/subcategories/3587/Sweetwater-Linear-II-Air-Pumps

the cheapest smallest sweetwater pump is like $198, so you might find a cheaper slightly smaller pump than that for only say 2-3 air diffusors @ 36"
I'm thinking the infamous luft pump is too small...
or just have a nice air valve and have lots of extra power for when you want it.
maybe someone else knows more about air pumps??

 

[fbacungan]

>wow, 4.5 x 36...wtf were these people thinking?? ...lol

Windows 95 was the greatest product since sliced bread....15 years ago.
I'm sure the downdraft was great back then, but technology makes things obsolete.

>and do you have a pic of the middle pumbing piece? is it filled with bio-balls normally?
I wasn't able to get the output valve off to see what's inside it. The screw that hold the valve has rusted off. After a few minutes of fiddling with it, I gave up. I'll have to tinker with it some more.

>....or you could go uber old school with a new twist: fine pore ceramic air diffusors and and a nice powerful air pump

Well, an old school skimmer may just have to stay old school. Thanks for the websites. I think I'll go this route first and see how effective it is.

Mark, thanks for your suggestions. I'll repost the final product when it's ready.

 

[coralfishg]

did you ever finish this project.. i know im digging it up from the grave but i have the same skimmer and whould love to see what you did to possibly super charge it..

 

[fbacungan]

Yes, I did. I made it into an in-sump skimmer. I took out the middle piece so that it could fit in the sump. I got a sicce pump with mesh mod as suggested above. I drilled a hole at the top section of the skimmer so that the bubbly flow goes down the pipe. Works awesome, particularly with the sicce pump. Creates lots of bubbles and have to clean out weekly.

 

[coralfishg]

any chance of getting a picture.. i think i understand what you did, but a picture is worth a thousand words.

 

[dhnguyen]

Personally with a tall skinny body like that I would just put some good micro pore airstones in and use a decent air pump.

 

[dhnguyen]

LMAO I see Skimmy said the exact same thing previously too