Skimmer operation

[aquablizz]

Is there a way to determine if a skimmer is working correctly.. Just not happy with the amount of skim being removed but then again maybe the protein just isn't there...

I am using a EV 180 on my 75 gal display tank which also has a 40 gal sump. This skimmer is being driven by a 900 gph pump which is setup only 3ft from the skimmer itself.
I run the skimmer 24/7..

I have a fish load in inches of approx. 16inches between 5 fish and I only feed once a day. I would have thought I'd be emptying the skimmer quite a bit but that is just not the case.

I basically have zero nitrites and zero phosphates but have always struggled with nitrates.

Any idea's or suggestion

Thanks in advance
Blizz

 

[CodyRVA]

Do you have algae issues at all? I mean, if your tank looks good and corals/fish are thriving then who cares how much skim you pull? If you had algae issues and the skimmer wasn't pulling much then yes I would imagine the skimmer wasn't getting enough/too much water/air.

 

[aquablizz]

Hi Cody
The fish all seem healthy but I do have some algae issues.. I do not keep any invert's or coral. I get a very light coating of brown (which I guess is algae) on all the substrate and rock that's in the tank.. I have to stir the substrate once a week to keep the bottom looking white but I really hate the brown on all the rock. I also have a small amount of the dark red cyno algae but not much..
I'm just not sure if I am tuning the skimmer wrong.. Thinking of putting it on a timer and let it run every other day.

blizz

 

[CodyRVA]

I have to turn my sand bed weekly, not an issue. As far as cyano/algae you may need to adjust the skimmer, assuming you're not getting much skim. Can you adjust the water/air on that skimmer? How long has the skimmer been running? If the skimmer wasn't able to keep up with the bio load you should be pulling a lot of skim, in which case you'd want to go another direction to solve the issue

 

[Kungpaoshizi]

Sounds like you're doing alright. Might add a drop of vinegar every so often, that should assist in nitrates. But it doesn't sound like the tank is too dirty, so you're probably correct, there's not much to pull out.

 

[CodyRVA]

I would make as small as changes/fixes as possible before doing something like carbon dosing. This can add more complications where as smaller changes like correcting the skimmer, adjusting flow, monitoring feeding, etc may be worthy alternatives. Avoid the rabbit hole.

 

[mcarroll]

That's a giant skimmer on the small tank.

It may have trouble skimming under any but the absolute worst conditions when there are tons of nutrients in the water.

If you aren't already running the air wide-open do so. You might have to downgrade to an EV120 though.

 

[Darryl]

I agree with mcaroll

 

[aquablizz]

You guys feel the AquaC EV180 is too big for 120 gals??? It's rated for 75-180 gal tanks so I fall right in the center at 120 counting the sump??...

 

[CodyRVA]

You guys feel the AquaC EV180 is too big for 120 gals??? It's rated for 75-180 gal tanks so I fall right in the center at 120 counting the sump??...

Plenty of good reviews on marine depot with tanks ranging from 90-150 so I can't imagine the skimmer is overkill...?

 

[rainmaker]

I would make small adjustments to water height in skimmer by adjusting the gate valve an see if that will help

 

[reef_junkie]

The aqua c ev skimmers are known to be dificult to dial in. They have a wierd venturi. Could be that its not tuned right. Id think that daily feedings would be enough to skim.

 

[Collinw24]

I had an EV-240 running on my 180 for about 5 years. Worked great, pulled out a ton of gunk. I just recently replaced it with a Reef Octopus Elite 220. The RO is pulling out about the same amount of gunk, I just didn't like having to have a bigger pump running my skimmer (mag 18), than the one returning water to my display.

 

[Elementalj]

The aqua c ev skimmers are known to be dificult to dial in. They have a wierd venturi. Could be that its not tuned right. Id think that daily feedings would be enough to skim.

Mine was a total pain. Water level in the sump needed to be absolutely constant.

 

[Elementalj]

PS there is no skimmer overkill IMO.

 

[mcarroll]

You haven't experimented with enough skimmers if you haven't seen skimmer overkill.

But that also implies you do a good job sizing skimmers!

@aquablizz:

It's worth reiterating - the EV-180 is big big for a 75 gallon tank.

That doesn't mean it can't work.

It means, as I said before, that it will have trouble skimming. That means - at best - it will be very touchy, skim very little and require more-frequent total-cleanings due to buildup that doesn't make it into the skimmer cup.

An EV120 or even an Urchin would be a better fit, just for perspective.

You guys feel the AquaC EV180 is too big for 120 gals??? It's rated for 75-180 gal tanks so I fall right in the center at 120 counting the sump??...

It's rated for a 75 gallon tank as a minimum.

They have no idea whether you have a sump at all or if you do, how big it is. That's not part of their rating.

This skimmer is being driven by a 900 gph pump which is setup only 3ft from the skimmer itself.

I missed this somehow on the first read.

I used a 900 GPH pump on my EV90 (and old, discontinued model that's a little smaller than the EV120) and it was right next to the pump, through an elbow. Granted, that EV90 was overdriven (a beast!) but I hope it makes the point that a 900 GPH pump on a EV180 is going to be the minimum if not a bit too small given your plumbing length.

I'd try upgrading the pump or shortening/simplifying the plumbing as much as possible.

Could be that its not tuned right.

This is also possible, but the pump and plumbing deserve consideration if this doesn't work. A Mag 9 or bigger plumbing or shorter plumbing would all have similar effect of boosting output.

Follow this method and you'll get it "as good as possible."

1. Get your skimmer initial adjusted as best you can without flooding out and let it run.
2. Check it 24 hours later.
3. Look at the skimmate quality and quantity
4. Ignore the current performance of the skimmer while you are making your adjustment.
5. Make an adjustment to the air (if possible) or gate valve (if that's all there is) based ONLY on the skimmate from the previous 24 hours.
6. Check it again 24 hours later.
7. Repeat #3 through #6 until the skimmer is kicking as much butt as it can.

 

[aquablizz]

Even though I have a 75g. display, doesn't the 30 additional gallons in the sump count for something??

Also my plumbing is basically a straight shot of 24inches from the pump to the skimmer with no elbows...

blizz

 

[mcarroll]

Not unless it has livestock in it.

Can you post a pic of the skimmer install? 3' is still long enough you may have to account for it.

 

[aquablizz]

I think at the most the length of the feed is 30 inches.. straight up from the first chamber of the sump..

This picture is 4 days of operation and that's the most I could skim..

Thanks
blizz

 

[mcarroll]

That doesn't look too bad. Consider ditching the metal clamp for a plastic click-clamp though. And I'd switch up the drain plumbing too, ideally. It may be fine for now (maybe not) but the elbows will cause enough backpressure on their own to cause performance issues and difficulties dialing in the skimmer. A straight shot with a 45º elbow on the end should be a bit better. I wouldn't stop for either of these things...just keep them in mind going forward.

Looks like you do have an air valve, but it's already wide open. I think you just need a higher water level in the skimmer - then you'll know for sure if you need a bigger pump.

Run through that dial-in proceedure a few times, making adjustments with the gate valve, and see what kind of progress you can make!

Remember not to make your adjustments too big all at once....you'll be likely to overshoot the sweetspot and miss it. I seem to remember making only 1/4 or 1/8 turns...something small like that.

Have patience and just plan on making many small adjustments over the next week or two.