Tunze 9002 Nano Skimming Water

[astralmind]

Hi,

I've had my Tunze Skimmer for a bit more than a month now and honestly, it has barely skimmed since I installed it. There is plenty of air coming in and the unit is properly positioned vs water level (water level half an inch under the water line). If I lower the air intake too much the foam doesn't go up but as soon as I let more air in, I get a very watery skimmate - to a point where most of the time it actually looks like clear water. I've seen some slightly darker skimmate come out for 2-3 days and that was it over the course of a full month.

I have a RSM 130 (34g) with plenty of bioload to be skimmed. What am I doing wrong ? I don't want to take it appart without know what to look for. Most of the info I found online said to either lower the water level (raise the skimmer) which I have done or check if the air intake was blocked (pinched tube) which it certainly isn't seeing the amount of air I can get in.

Any help would be immensly appreciated.

Thanks,

 

[rvitko]

The key is to adjust the air very slowly, it takes time for the foam to build and to see the result of the adjustment 1/4 to 1/2 turn per day is all the adjustment I would do. This skimmer is unlikely to ever product thick dark skimmate, a bigger skimmer is required for that result. It will generally produce a skimmate that looks like light colored iced tea. Make very small adjustments and give it time.

The only other thing that comes to mind is some additives and filter medias can cause this, known issues are slime algae killers, new filter floss or bags that are not phenol free, Purigen by Seachem, slime coat and stress coat additives and most vitamin and Amino supplements. These products change surface tension and affect the operation of just about every skimmer. The usual result is watery skimmate often preceded or followed by no skimming at all for a few days.

 

[astralmind]

Thanks for the reply.

I am using Purigen by Sechem and dosing (albeit very low volume) some Aquavitro Fuel in my tank. Are you recommending I discontinue using these products in order for the skimmer to perform adequately ? That being said I haven't introduced any Purigen in a while, the bag has been sitting there for a month now.

In terms of skimmate, I have seen a lot of people online getting some pretty nasty dark stuff out while the best I got was light green tea. My point is that the awful stock skimmer (which was loud, huge and cheap) didn't do a great job but at least skimmed - so far this one doesn't so there as to be an issue.

 

[rvitko]

I am not sure what is in Fuel, I would assume it is a sort of carbon source but I could not tell you what effect for sure it would have. Generally carbon sources feed bacteria that break down waste and encourage the growth of coralline algae and can be a food to corals, in some case they encourage anabolic reactions that build larger molecules that can be skimmed and this can result in watery/cloudy skimmate, I just don't know enough about the product to say whether it is adding to the problem or not. The norm is the light tea, you can in certain circumstances (skimmer raised high and very careful fine tuning) get a dark skimmate but this is not necessary and tends to reduce the overall amount of organics removed as the cup cakes up with sludge and impedes more skimming, unless the cup is cleaned often you will remove less than with lighter skimmate because after a certain point the foam no longer rises into the cup. I wouldn't discourage you from using anything, but the skimmer will skim lighter and erratically when these additives and medias are used. Purigen removes many of the same things a skimmer does, so there is less to remove and it seems to have some effect on surface tension that causes watery skimmate. Nothing you describe indicates a technical issue, I think it is either the result of the media or additive or just in need of more precise adjustment. If you get it to where it skims a green tea and try raising it 1/8" or closing the air 1/8-1/4 turn you can likely get the skimmate you want, but I would remove the variable of the additive and media for the sake of this adjustment and then later add it back if you wish.

 

[astralmind]

I am not sure what is in Fuel, I would assume it is a sort of carbon source but I could not tell you what effect for sure it would have. Generally carbon sources feed bacteria that break down waste and encourage the growth of coralline algae and can be a food to corals, in some case they encourage anabolic reactions that build larger molecules that can be skimmed and this can result in watery/cloudy skimmate, I just don't know enough about the product to say whether it is adding to the problem or not. The norm is the light tea, you can in certain circumstances (skimmer raised high and very careful fine tuning) get a dark skimmate but this is not necessary and tends to reduce the overall amount of organics removed as the cup cakes up with sludge and impedes more skimming, unless the cup is cleaned often you will remove less than with lighter skimmate because after a certain point the foam no longer rises into the cup. I wouldn't discourage you from using anything, but the skimmer will skim lighter and erratically when these additives and medias are used. Purigen removes many of the same things a skimmer does, so there is less to remove and it seems to have some effect on surface tension that causes watery skimmate. Nothing you describe indicates a technical issue, I think it is either the result of the media or additive or just in need of more precise adjustment. If you get it to where it skims a green tea and try raising it 1/8" or closing the air 1/8-1/4 turn you can likely get the skimmate you want, but I would remove the variable of the additive and media for the sake of this adjustment and then later add it back if you wish.

Excellent support, thank you very much!

I am getting more concerned because I will be adding BioPellets soon and one of the crucial point seems to be "excellent skimming ability" so... Fuel is a vitamin additive for Coral growth (Iodine, Iron traces, Calc, Mag etc..) so I don't know if it would have an impact but I like this one. Purigen was added as a recommendation from some one online - this one I could very well remove if it help the skimmer do a better job!

As it stands right now, water level is half an inch under the water level line which I guess is appropriate. The air intake is very low, maybe 1.5 turn. As it was this morning, no foam overflowed so if nothing got up during the day I'll up it a bit tonight (1/4 extra turn seems to make a drastic impact).

So even if the skimmate appears as very watery and almost clear, it is actually considered as "working" ?

Thanks again!

 

[rvitko]

It sounds like fuel is just a trace element combo, this wouldn't have any effect on skimming. Try removing the Purigen for now, it removes organic material, the same things the skimmer is removing, I am not sure how it works but given that it is recharged with bleach my suspicion is it oxidizes organic material and this does result in clear watery skimmate, ozone does the same thing. Keep in mind it may take a few days for things to go back to "normal" with the Purigen removed.

The skimmate should not look like water, but it can be light, it should be light green, light brown, very similar to green tea or light iced tea. In some case it may even look cloudy/milky, it just depends on what is being skimmed. Try with the Purigen removed. I don't think the purigen is harming your tank, but it is competing with the skimmer, so for the purposes of testing/diagnosing the skimmer, we want it out and if you add it back later, just know it does affect the skimmer.