Sump project?

[Camaro95]

As you've noticed, I've started posting again which can only mean one thing; summer is over and winter is coming. Given that indoor weather is currently upon me, a new slate of projects (albeit smaller than last year's failed biggie) awaits.

A couple have already taken shape and are progressing well and may be revealed sooner than later. However, I need some help with a sump. I've read a ton of different instructions and still don't quite understand. Colour me stupid I guess.

I have a 30 gallon I plan on using. From my understanding I need an overflow box because I don't want to drill. So I guess I make an overflow box to keep the fish out of the siphon. The siphon then leads down to the sump which will have 3 sections... the first is the intake with some substrate. The second is where the filter media will be stacked through a series of up-downs and the third is the return where I will throw in my heaters and submersible pump.

Now the questions I have (aside from the inflections above), are as follows:

Is the water level supposed to be equal in the first and last section or does it matter?
How do I calibrate the flow so the intake matches the return?

To break the flow during a power outage, I hope to have the water level in the main tank drop below the overflow level in order to break the siphon, yet not entirely fill up the sump. Is that generally how it's done? Just sitting there and adjusting it once or twice?

[RTR]

The general rule is that the top tank has a near-constant level. This is controlled by the overflow edge. Any water flowing into the upper tank will go over that barrier into the overflow assembly.

The overflow assembly is designed such that the siphon over the wall of the tank cannot be broken. This is controlled by barriers on both the inside and outside. When water stops flowing over the barrier, the siphon is not lost. The most trouble free units have pumps to pull any air bubbles out of the siphon chamber. That construction avoids any excess overflow in power-off situations, but restarts when power returns. The siphon itself does not ever extend to to the lower tank - it must be baffled such that it keeps the siphon intact when there is no flow.

You do not balance the flow -that would lead to disaster.. Flow is controlled entirely by the return pump's delivery volume at the release into the upper tank. If this is not at water level in the upper tank, there must be a "bleed hole" at or barely below the upper tank's normal water level to avoid back-siphoning via the return piping. Any air introduced in power failures is purged when the pump re-starts. The bleed hole must be brushed routinely to avoid clogging and disaster.

I generally use CPR overflows, with their pump and prefilter on the overflow box. The prefilter should be rinsed periodically. It is relatively trouble-free equipment IME.

[Camaro95]

Thanks RTR. CPR overflows are exactly the design I was looking for. Unfortunately the price isn't exactly for the frugal-at-heart.

From my understanding of the process (in order to maintain the siphon in event of a power outage), the overflow box allows water to enter at a predetermined depth (say 2 inches below the top of the aquarium). The water then enters the siphon somewhere nearer the bottom of in-tank portion, travels up and over the top of the aquarium and down the back end of the siphon to the outter portion. Now the outter portion is divided into two areas, the siphon-out and the overflow-to-sump connection. The divder between those two section should be equal in height to the predetermined water leverl in the tank, in this case, 2 inches below the top of the aquarium. Is that the correct relationship for the siphon?

[Pufferpunk]

Have you seen Melev's site on sumps?

[Camaro95]

That is a ton of information. I will need a couple more read throughs. I can't believe how many different ways there are.

I think I may need to experiment with heating larger pieces to bend them into shape and "weld" them into place, rather than silicone.

Looks like I was on the right path but now I almost understand why.

Apparently it doesn't matter too much the height of the baffles when compared to the water level in the tank. All that seems to matter is that the water level is equal on either side of the siphon so as not to break it. Does that sound about right?

[RTR]

I really only mentioned CPR as a good model to follow. It is a bit more sophisticated than the oldest design units I have and those CPRs have been the most trouble-free in operation for me.

I actually prefer the much older Vortex design, which has a variable standpipe in the rear compartment. My preference there is that it give me better control over the water depth in the main tank (rather than having to play with the screws that set such on most units) and the (to me) main feature that it uses deep water pick-up from the tank rather than surface overflow. Surface scum is rarely an issue for me, and I hate having to use feeding rings if I feed flake or floating pellets. But that design I have not seen well-pictured anywhere on the web, and the units are over-priced for the current market. So I actually use more CPRs than Vortex units. The Vortex unit interferes with cover glasses more often also, and is available only in one size - which is absurd.

My plastic-working skills are very weak, and my equipment nil. I DIY a lot of PVC/CPVC, but not sheet goods. So I have never attempted anything as complex as a sheet plastic constant-level siphon.

The pump CPR uses to keep the unit bubble-free is available under its own brand name, which I have forgotten, but I can check and post it later if you want - it too is quite good and low-energy use. The CPR model has a hanging loop and the standard model does nor, but that can be DIY'd relatively painlessly if you need such.

[Pufferpunk]

I have a HOB Fuge/skimmer FS. Made by Nova, 22" x 16" x 4.5". Sold new for $325, looking $100 for it.

[HGI]

Hate to flood this area but I also have sump stuff for sale if your in need,
Overflow box rated for 600gph, Return pump,A 2.5 gallon of bio balls,10 feet of braided vinyl hose (new never used).
PM me if your interested and I'll give you the full details.

[J-P]

Cam have you seen my tank?

If the power cuts, the flow stops. No flooding. When the power starts there is no need to purge the lines. Very simple, power UP, gravity down model. The only draw back is that if the pre-filter gets clogged then you have a MASSIVE flood

RTR helped me configure the media after the first few attempts and I got it right finally.

Think of it as a circle. It doesn't matter how fast you go, you're going as quickly as the pipes and media allow you to go. But mine is drilled