water turned grey after UV install

[tamara]

Well, today we finally got some time to install our custom 15 watt UV filter. It is powered by a powerhead which is sitting on 2 #3 sponge filters, stacked. It's hanging on the side of a 72-gallon tank.

Everything looked fine; however, after it was left alone for a couple hours the water has turned all dark grey. The fish don't seem bothered but it isn't pretty.

Any suggestions?

We have turned off the powerhead as a temporary measure.

[Carl]

I have honestly never seen this in ANY UV install

Can you provide a picture?

Did some contamination get into the UV or filters between receiving and installing?

Carl

[Carl]

Another thought;
Try a sniff test on your sponges and UV.
If is smells funny, rinse all out well.

Another thought is if you used any medications, as although I have not seen a tank turn grey from initial installation, I have seen yellow and other hazes from interactions with medications, in particular quinines


Carl

[tamara]

Thanks for your quick replies.

I can take a photo, although that would take some time.

Basically, it looks like there is charcoal dust in the water. Because of this appearance, we just now took out our own charcoal cartridge from our HOB filter for the heck of it. When we dripped the water from the cartridge into a white container we can see tiny black particles in the water. It could be that the meshy stuff on the cartridge was capturing the black particles.

When we take water from the top of the tank instead, a small amount in a white cup looks pretty much transparent.

As another point of information, when we were moving things around today, the sponge pre-filter came off the HOB, and Kevin then had to spend a fair amount of time cleaning plant matter out of it. So he was messing with the HOB, which does have a charcoal cartridge. However, the charcoal cartridge looks completely fine, and it's hard to imagine this being the source of the black particles. The charcoal cartridge is old, so it shouldn't have that "new charcoal" effect.

There is a tiny remnant of a medicated wonder shell in the tank. Some weeks ago we used some other meds but nothing strange and there have been multiple water changes since that time.

Again, the fish look fine, so it isn't urgent in that sense, it's just that if we don't solve the problem reasonably soon our plants will suffer from lack of light. It's really quite dark.

We have an old Whisper Diatomagic that is missing its filter media but we still use it with a makeshift microfiber cloth as filter medium. Maybe we'll try that first.

[tamara]

Here is a photo Kevin took some time ago. So this is "normal".

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[tamara]

Here is our aquarium now. This is a vertical photo so you can see the color of the wall in the background. We would normally be seeing the wall through the aquarium.

Sorry the photo is sideways

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[tamara]

OK, here's another from today. It's a similar shot to the photo of the normal tank so maybe it's easier to compare.

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[tamara]

Also, FYI the sponge filter was operating fine for a couple weeks or so before today. The only thing we added new today was the UV. It's really hard to imagine how this effect could be caused, isn't it!

[tamara]

One more thing we noticed....

Before, when we had the powerhead only hooked up to the 2#3 stacked sponge filters, without the UV unit, there was a very strong outflow.

Now, after hooking up the UV filter, the outflow is very weak.

We were expecting some diminishing of the output but were surprised by how much it decreased.

Also FYI we have not opened up the UV unit so I don't believe we could have introduced anything to it.

[Carl]

What pump is running the Sponge Filters/UV?

Reduced flow depends upon pump used, the Custom UV has a long flow pattern that requires more head pressure.
I assume it is hanging on the back, if not, make sure it as close to the height of the tank top as possible.

Back to the gray cloud, this looks like something else was introduced somehow, I just do not see how a UV could do this, but I will not state this categorically.

The fish look quite undisturbed, which is a good sign.

I would suggest running some water parameter tests.

I would suggest a 25% water change followed by another in a day or two

Carl

[tamara]

We are using the powerhead that came with the #5 sponge filter kit. (I was told by customer service this was recommended for running the sponge filter with the UV.) We originally were planning on running it with a #5 and #5 stackable but decided to trim down a bit and use 2 #3's instead, so that's what it's on.

The UV unit is hanging on the back (or actually the side corner). Due to space issues, the intake hose going into the unit is looping around the UV unit because it just didn't work to have it go straight in, so that lengthens things somewhat.

It doesn't bother us if the flow is low so long as this is normal operation. It just seems like there can't be a lot of water going through the sponges at this rate. But then, what do we know?

I agree, it really doesn't seem possible for the UV to cause the greyness. All it is is basically a pipe with a light bulb, right? It doesn't seem like fine black particles could come from that unless a very strange mistake was made in assembly and that seems extremely unlikely. The only reason for our initial suspicion was that the UV unit was the only item introduced to the tank just before the greyness set in, but more and more that seems like it must be a coincidence. You know, post hoc ergo prompter hoc and all that.

Yes, as near as we can tell the fish are unbothered by it all, which lowers our stress level considerably.

Kevin is wondering if some normal aquarium gunk could have come off the sponge filters and gone back into the water. It doesn't seem likely to me. What do you think?

It really looks for all the world like charcoal dust. I have done some internet searching and have found almost no mention of this, except of course to tell people they need to rinse new charcoal before use. However, there was one person who said while she was at work her charcoal began to disintegrate for unknown reasons and she came home to greyish water. If this is actually what happened to her, it apparently isn't very common. However, I'll be investigating our charcoal cartridge next, as I really can't think of anything else it could be.

We will definitely be doing a water change today, and water testing is probably a good idea. Also I think we'll run the UV unit into a plastic bucket just to confirm nothing dark is coming out if it.

[Carl]

Tamara, the pump that comes with the kit should be OK with the UV, although it is a low head pressure pump and cut the flow about in half (which is OK)

I personally build, inspect, and test every Custom UV, so there is nothing that would have gotten inside.

My best guess is carbon dust, but this too seems unlikely from what you have noted.

This is really a case of wishing I could see your tank first hand.

Carl

[tamara]

If you make the UV units yourself, we will assume that there is zero chance of something weird going wrong.

PH: 7.2
Ammonia: 0.25 ppm
Nitrite: 0 ppm
Nitrate: 5 ppm

Everything is normal for the tank except ammonia is normally zero. I think we can attribute this small spike to the fact that the primary bio filtration (stacked #3's) has been turned off since yesterday evening. (We don't test hardness on a regular basis so I'm not sure we would have a good comparison for you there. We only tested before we got the Wonder Shells.)

[tamara]

We have run the powerhead with the UV unit into a bucket of clear water, and as expected, it ran perfectly clear. It's running again in the tank.

All filters are cleaned and the water is changed. So now we'll see what happens.

BTW aside from a small charcoal cartridge and a few black plastic appliances, the other black item we have is a partial black substrate. Kevin added something that looks like black gravel to our ordinary gravel because it's supposed to help the plants. However I can't think of any way that would interact with the water to cause the problem. It's been in there for weeks.

Maybe Kevin's right and some black aquarium gunk came off the #3 sponge filters.

In certain lighting the grey color looks a little dark-purplish, in case that means anything.

If the problem goes away, we'll chalk it up to a mysterious freak occurrence. If it keeps happening, then hopefully we'll have new info by then.

[Carl]

Tamara;
.25 ppm ammonia is a normal spike in ammonia even without interruption of bio filtration
See Aquarium Nitrogen Cycle

I would recommend a GH test too.

As a side note, since you are maintaining a planted aquarium, I only suggest a minimum of Wonder Shell, so as to keep some mineral ions present.
Generally 1/4 to 1/2 the normal recommended amount of Wonder Shell.
For your size tank 1/2 to 1 full medium wonder Shell.
See Wonder Shell (& use)

Carl

[tamara]

OK, thanks for the notes.

After the water change and filter cleaning, the tank looked slightly better. Since then we turned everything back on and it is now looking worse again. (This is just subjective and we are talking about shades of grey, but both Kevin and I see it this way and, at least in my case, it wasn't what I was expecting.)

I did the hardness tests, using API test kits:
GH test 15 drops (off the chart; 12 drops would be 214.8. I think 15 drops would be 268.5.)
KH test 2 drops (35.8)

I'm not sure if I did the KH test correctly. The first drop turned the water blue, the 2nd drop turned the water pale yellow. Beyond that, I don't know what they mean by "bright yellow" so I don't know what to say.

These numbers seem odd.

The type of black substrate Kevin is using is called "eco complete plant substrate", in case it matters.

We're going to turn the UV off again and see if the water will return to normal. Then we'll turn it back on and see what happens. This just seems so strange.

[tamara]

It is definitely much worse than it was right after the water change. I have searched and searched on the internet and can't find anyone who has had a similar experience.

BTW we removed the charcoal cartridge this morning from our filter so that could not account for the greyness getting worse after the water change.

I'm stumped.

[Carl]

First I think you are doing your KH & GH tests correctly and these numbers while not perfect are not unusual.
Your GH number is fine, while your KH would be a bit better if it took 3 or 4 drops.

However at this point I do not think it is the problem.

Back to the issue at hand.

I think turning off your UV is a good idea, as each item needs to be eliminated.
Then perform another water change and note if the grey returns at the same rate.

EcoComplete may also be part of the problem, I will try and remember what some others have told me about this product.
While I have had no experience with it, I know it is not a favorite of my professional aquarium maintenance friends who have.
This said, this may have nothing to do with it.

Carl

[Carl]

As I noted in my last post, I would go with no UV for a day or two with a water change.

HOWEVER I did some reading to see if I could jog my brain and one point that I know I personally do not like about Eco Complete is that it contains contains live Heterotrophic bacteria.

The addition of large amounts of Heterotrophic bacteria can cause problems and it is possible that the UVs action on these bacteria in the water column could further exasperate the problem.

How long ago was the Eco Complete added?

Carl

[tamara]

We think it was added over 2 months ago. Kevin also put in a red substrate called Seachem "Flourite" at that time, which caused a temporary brown haze, but that seemed to be a result of insufficient rinsing and it went away in a few days.

I don't think we've put anything in there that isn't also in use by a whole bunch of other aquarists. And UV has been around a long time and is a well-tested treatment. Which is what makes it all so strange.

BTW the grey seems to be getting a little better on its own. It's a slow process. However, Kevin figured out a way to double the lighting on the tank, so now we aren't so concerned about the plants.

My main concern is that, in the end, we'll be able to use UV without having this happen.
Tamara