Overflow Standpipe Question

[coolcorals]

This is my first reef ready tank. I think the PVC CADLights sent for the Durso standpipe is too short. It's 10" long, which puts the top of End Cap 5" below top edge of overflow. I've posed the question to CAD, but so far no answer.

If you have a CAD 39g Pro, how long are your PVC pipes (one between bulkhead and "T") for both the 1" Durso and 1/2" return?

If no measurements, how tall should the Durso be - should the End Cap with hole be above or below water level in overflow? I assume below. If below, how far?

I want this to work properly without making a lot of noise or mess!

Thanks.

[1DeR9_3Hy]

5" sounds a little much to me, but i have no experience with cadlights systems. Here is my standpipe for reference, its a little tall but until i have to remove it for some reason it will stay that tall.

http://i45.photobucket.com/albums/f80/jgs240/DSCF1419.jpg

[coolcorals]

Your End Cap is above the water. Based upon photos I've seen and the length of my PVC led me to think it should be below water level! I agree, I think mine is short.

Does it just not matter whether it's above or below water level? Is one configuration preferred over the other?

Thanks for the response and photo.

[1DeR9_3Hy]

The cap has to be above the water level in order for the durso standpipe to work correctly. If you turn your system on right now with the standpipe that is 5" below the overflow you will have a decent amount of noise and probably a micro bubble problem to boot.

[BillyBee]

Try http://www.dursostandpipes.com/ explains where and how high.

[coolcorals]

1DeR9_3Hy: Thanks for the confirmation.

BillyBee: Excellent site for the Durso standpipe, and I had checked there, but missed that piece of info on first read.

After getting no response from CADLights, I email Rich Durso about his standpipe, and he confirmed that the end cap should be above water - he recommends at least height of aquarium, but a little taller is fine, for the drain to function properly.

I plan to replace the CAD included 1" PVC Durso for the proper size for a 1" bulkhead, which is 1 1/4" PVC.

Thanks again for the helpful responses and I highly recommend the DursoStandpipes web site - at this point, I don't recommend the CADLights systems (this is not my only issue with the system).

[1DeR9_3Hy]

What else do you not like about the CADlights system? I always wanted to get one but never felt like i would get my moneys worth from one.

[2_zoa]

I am not familiar with the cad tanks. If you have an internal overflow like 1DeR9_3Hy then regardless as to how long the pipe is the cap will always be above the water. The determining factor of the water height in the overflow is the weir created by the T section in the pipe. Water cannot flow up hill via gravity. I would assume that the pipe is shorter so that you won't be able to see it when viewing the tank. You will have a lower water level in the internal overflow then in the display. In the event of a power outage it will continue to drain until it cant drain any more which is dictated by the height of the overflow. Water dill drain down to the lowest point of the overflow and then stop. The stand pipe will drain until it sucks in air causing it to stop. When the system stars back up then the water will flow over into the area where the stand pipe is and then once suction is created again, it will flow like normal. If you have external pipes then yes I would say to have the caps above the water.

Also on the back syphon issue. Don't overlook the returns. It will back syphon through them as well. I think 1DeR9_3Hy has a very nice example of this. The returns are nice and high, just about the same height as the top of the overflow.

[coolcorals]

I guess most of my issues are nits, but you get what you pay for. So far the tank seems good quality and stand decent, but drilled holes are very rough/chipped (a nit). I had to resilicone the leaking inside panels of the sump (decided not to contact CAD for a replacement). The other equipment is marginal. The light seems okay, but it is very heavy. Rest of equipment is no-name - nothing came with instructions and many items were just wrapped in brown paper or bubble wrap - no box!

I'm not impressed by their customer service or QA. Since the system came with no packing list, none of the components came with instructions and the instructions I did finally get for stand were wrong and for different stand! It was a pain to get the missing parts I needed, since I had very little to go on, but knew the two doors with four hinges would need more than 5 screws to be attached (they require 16)!

The price is good, if you know how to put the system together. I plan to replace the fuge light (I've read it rusts) and pump (I've read it's loud and it's very large), and not use the UV. I've got my fingers crossed on the skimmer, but hear many people replace it too. Pretty much just leaves the light, sump and chilling fan.

I guess I was expecting the standpipes to be correct and consistent lengths. I contacted another CAD owner and their pipe is much longer. With it being so short, I'll get a loud waterfall in the overflow, which is exactly what the Durso should help prevent. According to the Durso site, the cap should be close to the top of the overflow, not in the middle.

Good point about the returns. I too plan to keep them high in the tank, plus will be adding a Check Value in the sump plumbing. I understand some folks will drill a hole in the returns to aid in preventing a siphon.

This is my first reef tank, so thanks for all the information. I'm sure I'm overthinking this whole tank build.

[1DeR9_3Hy]

Dont trust a check valve to hold water for too long, they will eventually let any water that is held back past it given enough time. I would leave it out of the design completly, its just another possible headache down the road.

What size (diameter) is the overflow tube now? Is this something you can rig together with some pvc and bushings?

[2_zoa]

Yea you are right about the water fall effect. The shorter the pipe is, the more chance you will get a water fall sound. There are some variables to that too. What kind of flow are you going to put on this thing?

On another note I thought that the cad tanks were sought after. Like I say I don't know about them maybe I wont bother looking them up.

[coolcorals]

1DeR9_3Hy: I plan to use both a Check value and Ball Value in the return line. First reef tank, so may be going overboard! The drain in overflow is 1" PVC, while the return is 1/2" PVC. According to the Durso site, the 1 1/4" PVC works much better than the 1". I'm in the process of building a replacement 1 1/4" Durso pipe. My original plan also includes a Ball value on the drain, but I don't think I'll have enough room under cabinet, unless I use a couple 90 deg elbows, so may scrap it. I'm thinking a fairly straight drain would be better than an "S" shaped one! Assume the drain is less likely to siphon.

2_zoa: I may've been a bit harsh on the CAD. The setup has been frustrating, but a learning experience! The CAD package is pretty cheap at $850+shipping for a full system. Stand is extra. The tank, stand and sump are pretty solid. Light is nothing fancy, but is 150w MH with 2 Actinics. I think they are saving money on the rest of the equipment. My biggest complaints are lack of QA and no instructions. I don't need much info, but a little would help. Though I did get help from Ocean Reflections and CADLights, it was much more work than I expected.

The pump is rated at 750 gph. I plan to replace it with a Mag-Drive 7 which has 700 gph rating. Initially, I plan add two Maxi-Jet 1200 powerheads for more flow.

I plan to add a build thread on Reef Central with photos, once I can get my act and parts together. ArtC has a awesome CAD 39g Pro thread in Nano Reefs forum, which has filled in a lot of missing CADLights info for me - check it out.

[1DeR9_3Hy]

Just try and do your plumbing as simple as possible. Unless you have upgraded your return pump/drain pipe diameter/return pipe diameter, i would not worry yourself with putting in a ball valce. CADlights probably spent a lot of time getting the flow just right, so the ball valve is probably not needed. I went overboard when i first did my plumbing, and it was over complicated. I had a leak from somewhere, so i had to take all my stuff down and luckily had the chance to re-do all my plumbing.

[coolcorals]

You're probably right. I'm more concerned with the return than drain for siphon. I wish as was as confident in CAD as you are. I'm also trying to account for any mistakes I might make - fear of a flood!

I'll be replacing the stock pump with a pump with same gph, but should be a lot quieter, so current piping should be okay.