50 gallon circulation question

[Ohmsford]

I have a 50 gallon reef tank with about 75lbs of live rock that has been set up for several years and has suffered numerous setbacks. Currently, I am trying to bring the water parameters up to adequate levels. I have minimal purple coraline growth at this point and the caluerpa in the tank is not thriving as it used to. I know I need large water change to correct this problem but I have been trying to bring the tank conditions up prior to doing so. So far the current conditions are:
Sg: 1.024
Temp: 78F
Ca: 480 (DIY CaCl / Baking Soda)
Mg: 1450 (DIY Epsom Salts)
Alk: 4-5dkh
Ph: 8.2
Nitrates: <10 ppm
Nitrites: 0
Phosphate: .1 ppm (organics are locking up the rest)
Lighting: 1X96W PC 10,000k and 1X96W PC Actinic 03 (needs changing)

Refugium/Sump: 10 gallons with a Coralife SW Mini light 2X9W on 24/7, 10lbs live rock, caulerpa prolifera and racemosa.

Circulation: External overflow box into refugium/sump with mesh bags of carbon and Kent Phosphate remover, returned by a Mag 7.

Protein Skimmer: CPR Backpack with airstone mod (Upgrading not an option at this point $$$)

Problem: Not enough flow in the tank. The Mag 7 return is piped with 1/2" PVC tubing. I plan on scrapping the 1/2" with 3/4" but am not sure of the best method of return. The current set-up has the return positioned in the back right corner of the tank, angled towards the center with the skimmer overflow in the back left corner. In order to maximize the pump flow (minimize use of powerheads) what would the best return scheme be for a tank of this size (50 gallons - 36"wide)?

I have toyed with the idea of a front or side facing spray bar, dual returns at the top, top and bottom returns, etc. I do have a second Mag 7 that I used on an old Berlin PS but am not currently using it. I would appreciate any feedback on how to minimize dead spots in this tank.

 

[Ohmsford]

After reading several posts, I decided against buying the SCWD. In theory it would have worked out great, but I can't afford sacrificing any flow at this point. This still leaves me with several options on how to plumb this tank. Any help would be much appreciated.

 

[ChrisRD]

IMO you're not going to get enough flow from the return pump alone and you should consider adding some powerheads.

Another possibility to getting more circulation from your return pump would be a penductor/eductor. I don't have any experience with them, however, and have no idea if a Mag 7 would provide enough pressure to see any real benefit.

 

[trido]

. I have minimal purple coraline growth at this point and the caluerpa in the tank is not thriving as it used to. I know I need large water change to correct this problem but I have been trying to bring the tank conditions up prior to doing so.

Caluerpa not thriving means that there are no nutirents for it to feed on. This is a good thing. By the looks on your parameters your coraline should start growing all on its own. It likes alot of Ca. and ALk. just give it time. Of course water changes are good things. But IMO not necessary for these two particular issues today. YOur ALK, Ca. and Mg look a little higher than ideal but nothing to worry over. What test kits are you using?

As far as flow. The mag7 may be an option if you are a DIYer. Check out this thread on a SCWD mod. MY 30G is set up much the same as your 50.
http://www.nano-reef.com/forums/index.p ... =scwd&st=0

 

[Ohmsford]

Caluerpa not thriving means that there are no nutirents for it to feed on. This is a good thing. By the looks on your parameters your coraline should start growing all on its own. It likes alot of Ca. and ALk. just give it time. Of course water changes are good things. But IMO not necessary for these two particular issues today. YOur ALK, Ca. and Mg look a little higher than ideal but nothing to worry over. What test kits are you using?

I am using SeaTest for Alk and Salifert for Ca and Mg.

I first decided for, but I had become undecided about the SCWD that I just scrapped the idea altogether to start formulating a plan so I can get started. I really don't have the time to do a SCWD mod, and would rather have it work the first time.

I like the idea of having closed loop circulation, but I do not want to drill the tank. I have seen a few non-drilled closed loop designs, but I do not like having the pump placed over the tank and having to prime it. If there are any other suggestions, I would be willing to give it a look.

Unfortunately, I am cursed at being rather capable at designing and maintaining a complex and expensive system, but fate did not leave me with deep pockets. So I am stuck at trying to work with the existing setup as much as possible.

 

[saltank]

I have a 46gal bowfront with a 14gal sump (hob overflow, return pump is mag 7) I have an aqua c remora hang-on skimmer on the sump powered by a rio 800.

The return is positioned toward the front center of the tank and I hava a rio 800 in one back corner and a powersweep in the other back corner. Probably 99% of the people on this board will tell you never to use RIO or the Zoomed powersweep (I am unusual in that respect). They have worked just fine for me.

The powersweep oscillates enough when combined with the other rio and the return line to create an awesome random flow in my tank. I have the mag 7 tuned back quite a bit but can open the throttle to create more flow when I want it at times.

This setup has worked great for me; you should consider added a ph or two to your main tank and creating random water movement ( I won't recommend the rio or zoo med brands just b/c of the bad rap they have gotten over the years in the sw hobby). But nonetheless, more flow and random water movement might help. :lol: