A question on flow

[AquaJohn]

How do you know how much flow you need I have read stuff that says anywhere from 5-12X water volume in an hour.

I have been fighting to get my phosphates down. My tank was not in a happy place and a 4 months ago I kind of was discuraged and deciding if I wanted to get out of the hobby so was lax in mant on the tank.

Anyways I decided to keep going and checked to find my phospates at 2 ya 2 ouch. So started with weekly 20% water changes blowing the rocks off with a baster I also added some dead rock to my sump < on hind sight probly a bad idea but was only 10-15 lbs > I have about 150-200 lbs of rock in my tank. My phosphates did not move from 2 after 3 weeks. I cut down feeding my fish 6 fish in about 150 gal of water none over 4"long. and 2 dwarf morey eels.I added rowphas <sp> the high power phosphate remover. After a week of that the phospates droped to .6 not sure if it was that or just a combination of everything. So I switched over to BRS GFO and carbon in one of there dual reactors and 2 weeks latter my phosphates are still at .5

Last week I added a second mp40 to the opposite side of the tank from my first mp40 and have been running them on the nutrient export mode I have them set at around 40-50% so I have tons of flow in the tank, I also have a Mag 18 return pump with a return on each end of the tank one of them goes though a chiller.Well my phospates are still at .5

I have considered vodka,vinager, or bio-pellets but seems kind of complex and would make it more complex to take a weekend off to go do stuff.

I had a talk with somone at a LFS and they said it might be a good idea to get a smaller return pump so the water stays in the sump longer and can go though the skimmer more before it gets sent back to the display. I had always thought more flow was better but it kind of makes sence. And with the 2 mp40s I can move enough water to pin my tangs to the side walls lol. So I don't think it would hurt to change to a smaller return pump than the mag 18 < before my mp40s it was my only flow>.

so what do you think

1 go with bio-pellets

2 dose a carbon sorce <vodka/vin>

3 get a smaller return

4 dont worry about .5 phosphates its not going to hurt anything you fool!!

5 use the tank for ar-15 practace

btw I use a red sea test kit so it is fairly ez to see what your low phosphates # are its an awsome kit and well worth the cost.

So what would you do ?

[AquaJohn]

Well after more reading im thinking its leaching out of the rocks still. Ill see what happens over the next few weeks.

[Juiceman]

I think you're already on the right track. Biopellet brought my nitrates down, but did nothing for the phosphates. Just rinse you food if you don't already, (helped my levels a lot!) How often are you feeding?

I have a mag18 on my 90, never had trouble, I think switching to a smaller return is the dumbest thing i've ever heard. but that's just my opinion on that.

Edited December 10, 2011 by Juiceman

[AquaJohn]

I feed daily still mostly diffent frozen stuff and flake but I have cut it down WAY less than I used to do I do not rinse the frozen. So when you say rinse it do you just get a cup of tank or rodi water and swoosh it around then use like a net and strain out the water ?

Im not sure about the return it kind of makes sence to let the water go thugh the skimmer more before its pumped back to the tank but ya my first thought was kind of no way more flow is better .

[AquaJohn]

I also do nori and just read that that sould be soaked before put in the tank too it holds a bunch too.

[subsea]

John,

Have you considered a more natural approach to removing phosphate. Microfauna and microfana in sandbeds uptake phosphate and produce food for reef inhabitates. Bacteria in deep sandbeds uptake phosphate and nitrates. A refugium with macroalgae allows both nutriant export (prune and remove seaweed) and nutriant recycling (feed tangs with seaweed).

With respect to flow in the refugium, slower is better, in my opinion.

With respect to flow in the display tank, it depends on what you have in the tank. Pinning the tangs to the back glass sounds like a lot of flow to me. Probably excessive. In this hobby, the word excessive does not seem to exist. If you were having a cyno bacteria "red slime" problem because of phosphates and low flow, the higher current in infested areas would be benificial.

Happy reefing,

Patrick

[AquaJohn]

ok I guess I should have made that more clear

its a 110 main with a 60ish gal 3 chamber sump one side is a refugium with a big chunk of cheto < a bit smaller than a soccer ball> shallow sand low flow also have a bunch of peperment shrimp in there my wrass seems to have a taste for them so they went in there . The main has a 1 1/2 - 2 sandbed. As far as pinning a tang to the side wall if I ran the vortecs at 100% im sure it would shove them around fairly well I was being sarcastic with the pin to the wall thing. I currently run the mp40s at about 40-50% power on the nutrient removal program. They do ruffle the surface a ton when they hit the big pull.

The returns I have one side pointed down ish and back at the center of the back wall of the tank to help with keeping the rocks clear. The other side is pointed fairly straight so it is always rippling the serface of the tank and kind of pointed at the center of the tank to get some cross flow. I do not have a speck of algae or cyno anywhere in the display there is some green algae and some red algae < I dont think its cyno its not slime> in the refuge side of the sump.

the other side of the sump is the skimmer a PM175 or 225 I forget what one I actualy got lol I was going for a 150 and they sold me on a bigger one because more is better lol. the center is the return pump. There is a bubble trap from the skimmer to the return and in that I put some of the black filter sponge so no crap from the drains get to the return from the skimmer side

There is a drain on each end of the tank they drain to a pvc bar that goes across the sump and one down spout to the skimmer and one to the refuge side. Each down spout has a ball valve and I have the skimmer wide open and the refuge has decent flow enough to move the cheto a bit but not sturr the sand.

As to why there is no alge I have no clue seeing as how high my phospates a full 2 were and nitrite .8.I do have to say that alot of my caroline algae did trun a dark red/marron and also a sickly green But now that the nasties are dropping I am seeing more bright pink again.

[subsea]

Getting back to phosphate export, continue to run phosphate resins for the bulk water. It sounds like you have phosphates in your substrate. Consider adding detrivore kits to kick start your sandbed. http://www.inlandaquatics.com/DETRITIVORES.html or http://www.ipsf.com/ . Get mature sand from someone that has established sand beds. Depending on the grainsize of your sandbed, determines which detrivore to target.

Chaeto is not the highest phosphate export macro. Caulerpa has the highest phosphate to nitrate uptake ratio. Depending on species of Caulerpa, as much as 200 fold when compared to Chaeto. Often when growing macro for nutriant export, iron is the limiting mineral. In other words, to get your vegetable filter to remove phosphate, you may need to add iron.

[+Mcjudge]

So there are a few things to take into account for flow. A rule of thumb is you want to match your return pump's GPH to your skimmer pump GPH. If you are running alot more water through your sump than your skimmer pump can handle then your skimmer never gets a chance to filter your water. Depending on the Head the distance between your return pump, and your outflow, I would also agree with the LFS as it seems like your return pump is over sized. 4-5 turnover through your sump is also what I remember is as the rule of thumb.

Then you get to the corals you are keeping, 10-20x turn over is a good goal to hit within your display. If you have a bunch of SPS there are alot of people that run 40-50X.

Not that I am the most experienced in the world but, me 50G tank, eheim 1250 300 GPH as my return, with 2x Koralia 2's 600 GPH each in the display. My return splits into my refugium and minus the head gives me probably 150-200 GPH return.(3x-4x) The 1200 GPH in the display is 25x..

Thats my 2 cents.

Cheers and Best of Luck!

[AquaJohn]

The tank has been up and running non stop for over 2 years and when I started it I purchased most 80ish lbs of real tonga branch + a 50lbs tonga bolder the tank it came from was 6+ years old <or so he said> and he got the rock from someone that had it in a tank for over 10 years if its true I duno but it had tons of live critters in it and in the 1-2 lbs of sand I got from his tank. I purchased the rock and transported it aprox an hour in styrafom boxes from his house to mine and it was paced in my tank cycled new water for about 2 months with the current sand bed I added his rock his water and the small amout of sand 1/2 to the tank 1/2 to the sump.

But you are right the sandbed is probly saturated with crap due to my negelct. I have had a diamond gobie and the sand sifter snails < I cant spell there name> the gobie died and was recently replaced with another. I also just purchased a 4-5" monster yellow head sleeper gobie on Friday and you can see stuff that is more fine than the sand being dropped by the gobies.

the Mag 18 is WAY bigger than the pump on the skimmer it basicly is split into 2 returns 1 has 2 90's and is about 36" above the return pump the other 1/2 goes though my chiller and to the return so has 3 or 4 90's .

The more I read the more I think its just build up in the rock and its gona take time for it all to leach out. ill have to pull the skimmer next time I clean it and see what size the pump is and decide what to do about the return.I know with 2 mp40's I can do way more than needed flow in the tank.

I do not have that much in the way of coral in there a few challace,frog spawn,hammers, a few blasto's. a couple hundred ugly greenish brown palys, lots of pink, white, dark purple sponge all over the dark parts of the rock.

Thanks for all the help guys keep it comin

[AquaJohn]

meh also 100-200 blue leg hermits 5ish turbo snails and a bunch of other snails. Im not sure how many emerald crabs I keep adding them when I cant ever find any but then a big one will pop up out of no where .

[subsea]

With respect to sand bed maintenance, I find snails more desirable than hermits. I prefer opportunistic scavengers (brittle and serpent starfish) over hermits. Snails are more beneficial to your sandbeds than hermits. There are several snail types that live in the sandbed and come out at night.