Algae Scrubber Basics

[Floyd R Turbo]

Screen is still filling in though, once you get a really good base of growth, the algae mat will be more even and consistent, and then the areas that are getting lower flow will start to get more and it will fill in across the whole screen eventually.

During the maturing stage, you are really only shooting for growth, and whatever kind you can manage to get really.

Yours is doing great

 

[Crusinjimbo]

Seefil, I use three of those Expression LED lights on a 12x5 (LxW) screen and harvest over 100g of wet algae every 8-10 days. I would recommend them for ATS service.

 

[DavidinGA]

Odd pH changes here....

My scrubber is about a month and a half old now (only my last harvest last week finally had a little handful of green algae I cleaned off) and my pH has dropped quite a bit.

I used dose Kalk and was running a day pH of 8.5 and a night pH of 8.3. I stopped dosing Kalk a few weeks after the scrubber came online and my pH came down to 8.3 day and 8.2 night.

Now fast forward several more weeks and my pH has inexplicable dropped to a day pH of 8.1 and a night pH of 8.0.

I am and have been since day one running my scrubber for 16hrs (most of those hours are when the main dt lights are off).

Any thoughts why my pH keeps dropping? I thought the scrubber should increase my pH right? Seems to be making it drop for some reason....

 

[SPotter]

Odd pH changes here....

My scrubber is about a month and a half old now (only my last harvest last week finally had a little handful of green algae I cleaned off) and my pH has dropped quite a bit.

I used dose Kalk and was running a day pH of 8.5 and a night pH of 8.3. I stopped dosing Kalk a few weeks after the scrubber came online and my pH came down to 8.3 day and 8.2 night.

Now fast forward several more weeks and my pH has inexplicable dropped to a day pH of 8.1 and a night pH of 8.0.

I am and have been since day one running my scrubber for 16hrs (most of those hours are when the main dt lights are off).

Any thoughts why my pH keeps dropping? I thought the scrubber should increase my pH right? Seems to be making it drop for some reason....

how old is your ph probe and when was the last time you calibrated it?

 

[mc-cro]

a lower kalk level can result in a minor drift downward of ph

 

[Floyd R Turbo]

If you have a lot of photosynthesis occurring, then yes. The presence of the scrubber does not cause O2 production, the presence of algae does. If you're not getting that much growth, then you are not going to get much O2 production.

Why did you stop dosing kalk?

 

[DavidinGA]

If you have a lot of photosynthesis occurring, then yes. The presence of the scrubber does not cause O2 production, the presence of algae does. If you're not getting that much growth, then you are not going to get much O2 production.

Why did you stop dosing kalk?

I stopped because my pH was inching up to almost 8.6 and I was under the impression the scrubber would push that even higher. Plus at almost 8.6 and dosing Kalk through my ato it left zero room for error if my ato got stuck and overdosed Kalk into my tank.

Is the scrubber actually making the pH drop...?

 

[DavidinGA]

how old is your ph probe and when was the last time you calibrated it?

It's only about 4 months old. I plugged the older pH probe in and the readings are the same for both probes.

 

[Floyd R Turbo]

I think that cutting off kalk dosing completely is the issue, couldn't you just have adjusted it to a lower setting? Seems like a drastic change in methodology in general, and drastic changes should never be made in a reef system when avoidable.

I personally have never really paid much attention to pH but 8.6 is not horrible as long as it doesn't stay there all day long. It's not where you want it to be if possible, but you should concentrate more on the long term trend. So backing off on the kalk, say by reducing dosing by 10-20% for a week, would have been my first step.

My experience with pH on a scrubber only system was that pH was more affected by the DT lights than anything else, the scrubber really just helped from pH bottoming out at night. So during the day cycle, when the scrubber is off, there is no photosynthesis occurring (at the scrubber, there is in the DT though) so how could the scrubber cause a pH to rise when it's not lit?

Granted that maybe your starting pH value at the point where the scrubber lights shut off and the DT lights come on is higher. So this may affect the overall peak pH value, but then you just have less reliance on Kalk for pH control. Now kalk for Alk and Cal levels, that's something different. Have you checked those? I'd be willing to bet that if you off Kalk these are dropping like a rock.

 

[DavidinGA]

I think that cutting off kalk dosing completely is the issue, couldn't you just have adjusted it to a lower setting? Seems like a drastic change in methodology in general, and drastic changes should never be made in a reef system when avoidable.

I personally have never really paid much attention to pH but 8.6 is not horrible as long as it doesn't stay there all day long. It's not where you want it to be if possible, but you should concentrate more on the long term trend. So backing off on the kalk, say by reducing dosing by 10-20% for a week, would have been my first step.

My experience with pH on a scrubber only system was that pH was more affected by the DT lights than anything else, the scrubber really just helped from pH bottoming out at night. So during the day cycle, when the scrubber is off, there is no photosynthesis occurring (at the scrubber, there is in the DT though) so how could the scrubber cause a pH to rise when it's not lit?

Granted that maybe your starting pH value at the point where the scrubber lights shut off and the DT lights come on is higher. So this may affect the overall peak pH value, but then you just have less reliance on Kalk for pH control. Now kalk for Alk and Cal levels, that's something different. Have you checked those? I'd be willing to bet that if you off Kalk these are dropping like a rock.

Ok.

I'm running 2 part through my reef angel so my alk/cal/Mg all stay in check (although I did up my dosing slightly after getting off kalk). Previously I was only dosing half rate Kalk (1 tsp per gal) through my ato and I probably lose 2-3 gal a day in evaporation.

I guess I could start Kalk back up at maybe a 1/4 rate...?

 

[Floyd R Turbo]

Kalk dosing is better than 2-part if you can because it's more ionically balanced, vs 2-part which is not (if you're using BRS or the like)

 

[DavidinGA]

Kalk dosing is better than 2-part if you can because it's more ionically balanced, vs 2-part which is not (if you're using BRS or the like)

Right, but Kalk can't keep up with my alk/cal demands and it raises pH too much for me to use it at full rate in my topoff (unfortunately).

Sounds like I should definitely go back to using some in the topoff tho....

 

[hobbzz]

Will my scrubber still pull nutrients if I turn the lights off for a few days, but leave the water running through it?

I'm not getting much production from my skimmer, and I want to keep the ats in limbo if I can for a few days while I make some adjustments to the skimmer and try to figure out if the ats is causing too much competition. I don't want the algae to die off, but also don't want it to be pulling nutrients out. How should I accomplish that in regards to the ats? Thanks.

 

[Floyd R Turbo]

As long as you provide flow, the algae will survive. After a couple of days I would expect that some of it would start dying off, but when you put the lights back on it, it will bounce right back. you might consider just knocking the scrubber light cycle down to an hour or two per day, this would definitely keep it alive longer and better.

There is very minimal nutrient uptake with the lights off, but I believe it still happens.

 

[hobbzz]

Thanks Floyd, that'll work great.

 

[SantaMonica]

A scrubber when full only has enough algae to raise pH by 0.1 or 0.2

Kalk can raise it to 8.6, or even 9.0 if overdosed.

 

[DavidinGA]

The pump for my scrubber is a brand new rio 2100 that is only a month old now. It has been seemingly loosing power and I will find it still pushing water but much much weaker flow arrghhhh. I have dismantled it and it looks brand new inside still (as it should) but I clean it anyways. The times that I have found the pump running slow I unplug it and plug it back in and I may have to to that a few times until it will finally all of sudden get full power (so I unplug it and plug it back in and sometimes it comes back on weak and sometimes it comes back on strong).

Thoughts? Is this simply a pump that's bad or does it possible have something to do with the scrubber setup or what?

Thanks

 

[Floyd R Turbo]

That sounds like a faulty pump if you ask me. Maybe try and contact the retailer and see if they will replace it? Or warranty from manufacturer?

 

[DavidinGA]

Got it on Amazon and I'm now past the return period. Arrggghhhh

 

[Floyd R Turbo]

Contact the manufacturer directly