Having proper water flow in your reef aquarium is extremely important to your reef’s health, especially when dealing with corals. It is so important that I would rate it up there with feeding, lighting and skimming. After all, proper water flow delivers food and removes waste from sessile organisms in the reef aquarium. Proper water flow also exchanges oxygen and keeps detritus suspended in the water column.
Getting the right type of water flow is often difficult to achieve in the reef aquarium because of all the options that are presented to us. On top of all the pumps, wave boxes and diy closed loop systems that you can utilize there is still the matter of placing this equipment in your reef aquarium so that you can reap the full benefit from it. Keep in mind that live rock and other obstacles in the aquarium can prevent proper flow throughout the reef aquarium if not set up correctly.
So what are the different types of water flow and how do us reef keepers use them?
Pretty simply there are two types of water flow for the reef aquarium that you should be concerned with. They are Laminar and Random. If you search on any online reef aquarium forum you may be able to find more in depth but not as practical ways of creating water movement. I say “not as practical” because most reef keepers will not be able to recreate these different water flow options as easy as the two mentioned above.
Laminar water flow is generally the easiest flow to create in the reef aquarium. laminar simply means one direction movement of water, as you probably guessed by now most submersible pumps and powerheads will produce laminar water movement. Laminar can get tricky, since it is a constant jet of water in one direction you will not be able to place corals directly in front of this stream. Most corals will not be able to last the powerful water jet and there flesh will eventually erode off there skeletons if exposed for long periods of time. Many reef keepers utilize powerheads and submersible pumps but do it in a fashion where it is less abrasive on corals, which brings me to Random flow.
Random water flow in the reef aquarium is hands down the best easily obtainable way of re-creating water movement similar to that of the natural reef. It is simply obtained by using laminar flow (powerheads, pumps etc..) against either obstacles such as the glass of the aquarium or against other laminar flow. Since there is no right way to create random flow in the reef aquarium because all reef aquariums are different, it is up to the reef keeper to try and test different ways to see which one is right for the aquarium. I personally like to direct two powerheads against one another (one on each side of the tank opposite of each other) to create this type of flow. I will then take another one and point it at the front pane of glass. The possibilities are endless with this type of water flow since there is no right way of doing it. Instead of using powerheads you may want to try a closed loop system which involves a large external pump and some diy (do it yourself) plumbing to avoid unsightly powerheads.
Which ever way you decide it is best to make sure that you don’t have any “dead spots” in the reef aquarium, dead spots are simply just spots in the aquarium with little to no water movement. These dead spots are where detritus will accumulate and if not removed can cause some problems with your reef aquarium’s water parameters.
So how do I know if my water flow is adequate?
Make sure that you have a good amount of movement in your aquarium, furthermore you should be able to create flow that will make your coral polyps extend and move around randomly.
My 46gallon Bow-front saltwater aquarium is a real show piece in my home. Friends, family and beginner reefers often ask me how I maintain such an aquarium with corals, an anemone, fish and various pumps and such. This is how I keep up with my aquarium maintenance.
Daily:
1. Top off water, I have a line drawn in my sump and I top of my water using only Ro/Di water.
2. Nightly checks on my cpr overflow to make sure that the air is releasing from the overflow and there is no blockage.
3. Scrape off the side of the glass to prevent filamentous algae from forming.
4. Clean skimmer cup.
5. Check for any general problems with the tanks inhabitants and plumbing.
Weekly:
1. Blow off live rock with a turkey baster then perform a 10% water change.
2.Clean powerheads if they need to be cleaned.
3.Wipe off light shield with a vinegar water solution.
4. Test water for any ammonia, nitrite and nitrate buildup.
5.Wipe off glass with a vinegar water solution.
6. Wipe off any salt creep that had accumulated.
Monthly:
1. Clean and maintain return pump and skimmer pump
2. Clean skimmer
3. Suck Any detritus that made it into my sump
4. Check calcium and alkalinity levels ( I mainly have a soft coral tank with very few calcium loving inverts, those of you with a lot of LPS and SPS corals should do this more frequently).
5. Change my phosphate media and clean out my phosban reactor. As well as change out carbon.
6.Test TDS (total Dissolved Solids) in my Ro/Di water.
Yearly:
1. Change light bulbs ( when needed sometimes its as early as 7 months).
A sump can do a lot for your saltwater aquarium. It provides a place to hide all of your equipment, and it increases your tank’s water capacity. Two very important things when you want to have a nice display reef aquarium but when designed correctly it can also be a place to trap detritus, filter your water and cool your saltwater aquarium. I use a simple sump on my 46gallon bowfront aquarium and this article explains how it is done.
The way my sump works is that water from the main tank overflows into a CPR overflow box that is pictured above. The water then flows down a 3/4″ vinyl tubing into my ten gallon tank in my stand. I use a powerhead to keep bubbles from being trapped in the CPR’s U bend. When deciding on an overflow box it is important to choose the correct return pump that will not exceed the gph that the overflow box can handle. Now if you bought a reef ready aquarium then you wont have to worry about an overflow box flooding or cleaning out an overflow box. On that note, I have been using the CPR style overflow box for over five years without any mishap. There are many other kinds of overflow boxes but that is for another blog.
The water from the main display aquarium rushes into the overflow box and down into the vinyl tubing you see on the left hand side of the above picture. I currently do not have a refugium but in the past I did have one on this tank. It used to be sectioned off where the water comes in the sump.
When the water reaches my sump it hits a filter bag filled with carbon, this reduces the amount of bubbles, saltwater spray and keeps the carbon moving. It also catches detritus which is important when you have a bare bottomed aquarium. In the sump I also have my phosban reactor, a glass thermometer, heater, skimmer, and a Mag 5 return pump that is hooked up to a SCWD. It is essential that I keep a nice quite system so by resting my overflow line and my return line on sponges it keeps down any hum or noise that may develop. I also have installed a smaller piece of tubing on my overflow line to keep out air pockets.
I currently use an Aqua C Remora protien skimmer (not the best but it does the job). It is a hang on back or hang on tank type of skimmer. It works equally as well on the sump or on the main display tank. I prefer to have as much room in my main tank for fish and corals and for aesthetics, so it is placed in the sump. The return of the skimmer pours out onto a plastic knitting sheet, If you have never seen one it is white plastic with openings about this [ ] big all throughout the sheet. This helps the water from splashing and aerates it at the same time. This plastic knitting sheet is placed in a tupperware container that is drilled with holes. I also have a bag of Purigen in the tupperware container so that when the water from the skimmer flows onto the plastic knitting sheet it goes right over the bag, keeping the Purigen moving.
Overflow Rating vs Return Pump
The return as I mentioned before is a Mag Drive 5 pump that has a Max gph of 500. My CPR overflow box is a cs50 which has an overflow rating of 300 gph, this means that when the CPR overflow box exceeds 300gph it overflows the box and you have a nice saltwater enhanced floor .
So then how do I get away from using a 500gph return pump? Since the Mag Drive pump pushes water through a SCWD it causes a small amount of friction and the water losses some of its momentum. The Mag Drive also has a head loss when pumping water straight up, At four feet the Mag Drive only pumps 310 gph. As the water reaches the top of the tank there is a little more friction as the water is pushed out of two directional U-Tubes. When all is said and done I estimate that the pump eventually pushes 290gph or a little less.
.