just a word about water flow

[keithinspokane]

just some observations of mine for others new to the hobby,hopefully it could be some help to someone sometime.this is about water flow.i recently added a maxijet mod 1200 to my 75 gallon and have been trying to figure out the flow situation.since it pretty much overpowers both the other powerheads and return line put together,it has been kinda tricky.
so...ive been moving the modded powerhead from here to there and back,a few times.and since im fairly new to keeping sps(corals in general),i didnt really know how much flow the sps could handle at worse,which i found to be quite a bit.BUT the observation i made was on a montepora,and an unknown acro.though the corals do like a lot of flow,they wont put up with turbulant flow for long.what was happening was,since the modded 1200 does overpower all the others,the tank naturally gets more flow coming from one side of the tank than the other,where there was counter flow occuring,it was creating a whirlwind/funnel affect with the water,causing mild tissue recession within 3-5 days with the acro,and i think it was like 1-2 days with the monti.i tried changing the powerhead setup once again with no luck.so it was time to move the frags to other parts of the tank.so far they seem to be recovering well,but time will tell.
so i guess my advice/point is,that if you get tissue recession from unknown causes(if your water parameters test within range,no nipping fish ect),maybe check the flow pattern in the tank.this little thread will problably suite people with smaller/shorter tanks,as with deeper tanks,high rate of flow seems easier to get high rate of flow without pounding every corner of the tank,as in my case,i have a 75 gallon with 47x turnover rate per hour,theres not too many low flow areas in the tank.which ive seen in larger tanks,its possible to get high flow rates but still have low flow parts of the tank for softies and such.thanks for reading,hope this helps somebody other than me

 

[Herefishyfishy]

Welcome to the site, good write-up.

 

[returnofsid]

Hmm interesting theory. Is there a particular reason that you attribute the tissue recession to flow? From what I've come to understand, there's no way a Modded MJ1200 is going to create more flow than an Acro likes. You mentioned "turbulent" flow. Could it be that with one pump over powering the others, that you actually had too much of a linear flow from that pump? If you were to have , say 3 Modded MJ1200s in the tank, creating a more random flow, do you think that would solve the tissue recession problem? WOW that's a lot of commas in that sentence...sorry about that.

 

[Snowboarda42]

I thought that modded MJ's were supposed to give a huge, wide amount of flow. It seems like if you had a regular MJ in there pointing almost directly in the direction of a coral it might recide.

 

[keithinspokane]

the modded 1200(high flow kit is 2400gph flow) does in fact put out a wide stream,it actually gets wider than my open hand about 5 or 6 inches away from the powerhead.also,the reason i attribute the tissue loss to the flow is,i moved the frags and it has stopped the tissue loss.and actually,to clear one thing up,in the case of the monti,it wasnt even really getting the turbulant flow,it was getting a constant one way flow against it(low to medium flow area) causing it tissue loss in a short period of time.as far as the unknown acro,only part of the frag was being affected.before i moved the frag i watched the water movement for periods of time to see if there was some type of pattern with the flow.and sure enough there is,about every 3-10 seconds,in the same little spot,the water was creating a small whirlwind affect causing it to almost whip the coral.i will update this as the days go by as i could be wrong,although i have moved both of them and they both seem to be doing better.
also hows it going returnofsid? i honestly dont see it possible to put 3 of the modded 1200s into a 75 gallon,ive actually had 2 in there....all i can say is whoa! i didnt know what to do.theres almost no way to have that much flow and still have sand.
thanks for reading

 

[returnofsid]

HI Keith. It's going well. Hmm, that's very interesting to know about the MJMods. Could you describe what type of mod it is? If it creates that kind of flow, it might just be something I'm interested in. Sure would be cheaper than trying to redesign my closed loop system again and adding an external pump. Although I think I want the external pump anyway. Do the MJMods create any more heat than a standard MJ1200?

 

[keithinspokane]

the mod is actually pretty simple to do,the kit comes with a shroud,a stainless steel rod,propellar,some tubing(rigid and soft),and a few other parts.here is a link of the instructions and the parts/things needed.the only drawback i have seen is the mount for it.i have founf that using the staright hanger with a suction cup on the bottom works the best,but this pretty much means the powerhead needs to stay at the top of the tank.maybe tomarow i will make a short video of it in action(during maybe feeding time so it can be seen well).returnofsid,i dont think the mod makes the pump create any more heat than it normally would.

 

[thumperss]

you can see the mod at mjmod.com i will tell you that if you mod the mj400
it will give you 2000 gph so if you think about it if you mod the mj1200 you are looking at around 3000 gph.WOW
Brandon

 

[thumperss]

Aquarium Systems Pump/Powerhead—Maxi-Jet, Mini-Jet & Micro-Jet
Aquarium Systems Maxi-Jet
Maxi-Jet®PH pump and power head is ideal for powering undergravel filters or creating internal water movement from its fully rotational output. The Maxi-Jet®PH incorporates a venturi aeration device to provide optimal aeration and gas exchange in the aquarium. A silencer keeps the venturi aeration device operating quietly. An adjustable air filter permits the user to fine-tune air volume and water mixing as desired. The intake tube adapter with prefilter screen prevents gravel or loose material in the aquarium from getting into the pump. Maxi-Jet®PH pump and power head includes an innovative triple-suction cup mount, an adjustable hook with cable guide, and a grid support for optional foam cartridge, and comes in a complete range of sizes.
High performance with low power consumption
May be used externally or submerged
Waterproof rotating water outlet
Silent, versatile, low maintenance
Protected motor will not overheat
UL Approved
Directional Flow Flap
Can be connected to 5/8" Flexible Tubing
Manufacturer Warranty: 2 years from date of purchase.

Model V/Hz Wattage Max Flow Max Pumping Height Dimensions
MP400 120V/60Hz 5W 106gph (400lph) 29" 3.5" L x 2" W x 3.00" H
MP600 120V/60Hz 7.5W 160gph (600lph) 53" 3.5" L x 2" W x 3.00" H
MP900 120V/60Hz 8.5W 230gph (870lph) 46" 3.5" L x 2" W x 3.25" H
MP1200 120V/60Hz 20W 295gph (1110lph) 69" 3.5" L x 2" W x 3.25" H
Note: The dimensions do not include any attachment or suction cups.

 

[keithinspokane]

http://s18.photobucket.com/albums/b112/rhino509/?action=view&current=mjmodflow.flv

sorry the video quality is crappy.i will try and find another means to make video asap.

 

[keithinspokane]

sorry for the link.
sorry again...lol,looks like it has to be a link instead of having the video right there.