Skimmer suggestions for a 90g

[daveverdo]

If something causes the skimmer to foam more than ususal it will overflow on your floor. Does this make sense?

Yes it does does make sense.

That is why I asked about having an overflow drain on the collection cup.

But then I was told that the cup overflowing isn't the problem, it is the feed pump draining the sump. With a downdraft skimmer there is no pump feeding the skimmer. That is what doesn't make sense. I am trying to understand how the the sump can drain if there if the only line connecting the skimmer to the sump is a gravity driven drain from the skimmer to the sump (as long as there is anti-siphon precautionary measures employed).

Dave

 

[fatrip]

ok here is one reason. you are splitting one over flow with one end going to the skimmer one goin to the sump. so if somthing get stuck or cloged in the one that goes to the sump, then inturn there would me more water flowing to the skimmer there for raising the height of the water in the skimmer making it over flow onto the floor. also if a fish dies and decomposes the skimmer works 10 times harder the amount of water and foam coming out will double or triple some times and if not checked would over flow onto the floor. alot of recirc skimmers that are home made have the top scred down and a side drain that goes into the sump. this prevents the skimmer from possibly overflowing but then you have back pressure on the over flow in the tank and could prtenially back up the tank to over flow. just telling you some things that could happen what ever rought you go. but ask any one around here esp people with 10's of thousnad invested in there systems they would not put a skimmer out side the sump or if they do they have atleast 2 check valves to shut off pump on the skimmer.

 

[fatrip]

"But then I was told that the cup overflowing isn't the problem, it is the feed pump draining the sump. With a downdraft skimmer there is no pump feeding the skimmer. That is what doesn't make sense. I am trying to understand how the the sump can drain if there if the only line connecting the skimmer to the sump is a gravity driven drain from the skimmer to the sump (as long as there is anti-siphon precautionary measures employed)."

it is the cup over flowing but it is over flowing faster than the little drain to the sump could ever handle.

 

[fatrip]

but we are talking about recric not the down draft. two totally different animals. altho water level in the skimmer will not be constant if fed the way you are thinking to either so it would potentially over flow any way.

 

[daveverdo]

if somthing get stuck or cloged in the one that goes to the sump

If the sump line gets clogged, flooding the basement is the least of my problems.

Anyway if that were to happen, the tank should still drain through the skimmer to the sump.

Dave

 

[fatrip]

if you put a certian amount of water in to the skimmer and have it so that it skims wet, about a cup a day. if that water line fluctuates up you would be pumping water onto the ground. the skimmer doesnt compensate itself for the amount of water going into it.
"Anyway if that were to happen, the tank should still drain through the skimmer to the sump. "

it wont there is a big hole in the top of the skimmer. if there is more water flowing into the skimmer it isnt goin to go to the sump it is goin to go out the path of least resistance....the big hole in the top...

i cannt explain it any better than that.

 

[daveverdo]

it wont there is a big hole in the top of the skimmer. if there is more water flowing into the skimmer it isnt goin to go to the sump it is goin to go out the path of least resistance....the big hole in the top...

Not if there is a hole LOWER than the top and the pipe from that hole can handle the amount of water coming in.

It should level itself to approximately the height of the lime out of the skimmer.

 

[frankandmaura]

That hole would need to handle a few hundred gallons per hour (otherwise it will fill the cup and overflow out the top).

 

[fatrip]

from what you are stating you dont understand the concept of how a skimmer opperates.

the output of the skimmer is regulated buy some sort of valve so it keeps the level of the water inside the skimmer at a ceritan hieght to skimmer well and is dependant on a on a constant flow of water into it to keep the water level. when more water is moving into it the water has no where to go but up and out. onto you floor.

there are some great articals out there on how skimmer work and flow. i suggest you read some of them before going on and building one. i dont mean to sound mean or snotty but from the answers you have given us i dont think you truly understand how water flows threw a skimmer. i say this because i dont wawnt to see you flood your basment and get fed up and get out of the hobby.

 

[daveverdo]

I understand how a skimmer works, most DIY counter current and some recirculating skimmers control the height of the water column by adjusting the height of the overflow.

I will admit the recirculating skimmers shown above do have valves to adjust the height of the water column but not all.

The DIY Snailman design I mentioned earlier is one of the skimmers where the water column height is set by adjusting the height of the skimmer output. If the height of the skimmer output is lower than the top of the skimmer it will not overflow. If you look at my diagram there is a 3/4" feed and a 1" drain, both gravity driven. As long as the drain is larger than the feed there shouldn't be a problem (barring a clog).

Dave

 

[fatrip]

but the level of the bubbles are dependant on how many disolved solids are in the water collum as well...the DS go up the bubls in the skimmer bubble higher...you arnt getting what i am say its ok...do what you will. i have seen it first hand a few times. its your basement and living room not mine. im srry that i can make you see.

 

[daveverdo]

Please don't insult me and tell me I don't understand. I am a physics professor and understand perfectly well the physics of the operation. I have been in this hobby for 35 years.

If you have seen problems, it is most likely because precautions were not taken, the device was a poor design, or the skimmer was not installed or operated correctly.

Dave

 

[fatrip]

we're not tryin to insult you we are trying to help but you wont listen. also Tell Nate (who has one of the 2 best tanks in the area) that he has a poor design i'd like to see what he says.

 

[Conesus_Kid]

<a href=showthread.php?s=&postid=12578470#post12578470 target=_blank>Originally posted</a> by daveverdo
I understand how a skimmer works, most DIY counter current and some recirculating skimmers control the height of the water column by adjusting the height of the overflow.

I will admit the recirculating skimmers shown above do have valves to adjust the height of the water column but not all.

The DIY Snailman design I mentioned earlier is one of the skimmers where the water column height is set by adjusting the height of the skimmer output. If the height of the skimmer output is lower than the top of the skimmer it will not overflow. If you look at my diagram there is a 3/4" feed and a 1" drain, both gravity driven. As long as the drain is larger than the feed there shouldn't be a problem (barring a clog).

Dave

I've looked at the Snailman design, but have not seen a CC skimmer in operation first-hand.

A couple of thoughts: The Snailman webpage I found (http://www.hawkfish.org/snailman/skimmer101.htm) was last updated 7 years ago; long before the advent of many of the efficient, low cost, in-sump needle wheel skimmers that are available today. For what you spend in materials, you can get a great skimmer that works right out of the box. From what I understand, those basswood airstones gum up fairly regularly, again, adding another variable to the equation. If you're more into "set it and forget it", you may want to avoid the CC design.

From reading this thread, there appears to be a "communication breakdown". I don't think that folks who have commented are concerned about your flow design through the sump and skimmer. The reason for concern is those infrequent times when the skimmer foams like crazy, popping the lid off of the cup and pumping lots of gallonage through the top of the skimmer cup!

If your skimmer is not in the sump, this overflowing cup will send the water on your floor. Even if you have some 1/2" tubing going to a collection container resting above (or in) your sump, it is possible for the skimmer to overflow through the cup faster than that tubing can carry the watery "skimmate" away.

I have only had my skimmer behave like this once, and I couldn't have predicted it. (I hadn't made any adjustments or changes to the skimmer. It sits in 9" of water in a sump chamber that does not fluctuate in water depth.)

Luckily, my skimmer is in the sump! I didn't measure the rate that the cup was overflowing, but I'd estimate is was more than 100 gph.

I know that lots of people have good luck w/ an external skimmer. Personally, they make me nervous for the aforementioned reason.

HTH