IndianMaidn

I purchased a 75 gallon salt tank w/ 20 gallon sump. It has an overflow box with a 1 3/4" (?) hose out the bottom into the sump. How do you tell what GPH this setup is. I need a new return pump. The one I have is really noisy (old) and it's apparently too powerful. It has an adjustment valve on it but it's really hard to get it right. All I can read on it is Rio 600 ? Is there a way you could tell me what size pump to look for ? The distance between the pump and top of aquarium in 4' 1". Also, I keep getting air bubbles in the overflow box on the back of the aquarium, which in turn collects in the elbow, is there a simple reason why it is doing this ? Seems like the water is entering from the aquarium too fast, but if I lower the box into the tank, it doesn't fill like is should. UUGGG !
Thanks in advance

agsansoo

Is the hose from the overflow box 1-3/4" ? Usually the hose or PVC pipe is 1". This is i.d. not o.d..

IndianMaidn

Yes, I'm sorry. It actually is 1". I've never run a sump before and I'm learning as I go along. The pump that came with it is noisy and I'm afraid it's going to just up and quit and as far as I have to turn it down, I know it's way more than I need.

aquarist48

Hello. I had a 72g freshwater tank with a wet/dry filtration system. I used a Mag Drive pump with 750gph and it did a wonderful job. Salt may require more filtration so hold on for some more responses to be sure.
Best of luck.
Ken

pepetj

I copy this info as guideline, it will allow you to estimate the maximum flow, based on PVC diameter you can expect to handle.
3/4" = 330 GPH
1" = 600 gph
1 1/4" = 910 gph
1 1/2" = 1,300 gph
1 3/4" = 1,800 gph
2" = 2,350 gph
2 1/4" = 2,960 gph
2 1/2" = 3,650 gph
2 3/4 = 4,450 gph
3" = 5,280 gph

Please check if this is the Rio pump you have:

http://www.marinedepot.com/Taam_Rio_...TA3191-vi.html

That said, a Rio 600 seems to handle 200GPH easily. I did noticed that the flow rate for this pump is not available in some pages, this is likely to the special venturi system it has. This pump seems great for SW as it chops air bubbles with the impeller aiding the protein skimmer (when the set up allows for that to happen: I place the protein skimmer in my Nano SW sump before the pump).

Your tank requires a pump that in the chart provided by the manufacturer should give you the flow you aim at having at 4' head.

In order to find out if your pump is overmatching your sump capabilites just observe the inside the tank overflow box. When a pump is too strong it will flood the overflow box and the water level will be either the same or end up raising the level of your main tank and cause a major water spill: it will flood.

For a propper set up, you want the water level inside the overflow box to remain at least a bit below the tank water level. I keep my overflow running slow (injected CO2) so I get easily 2"+ difference.

If you are getting a lot of air bubbles, it may be that your Rio pump 600 venturi system needs to disconnected.

If you want to replace the pump, consider purchasing an adjustable one that can deliver within the 200 to 600GPH at 4' of height. Submersible pumps make less noise than those placed outside the water (in my limited experience with the latter).

Pepetj
Santo Domingo