Question about the RDP Article

After reading the RDP filter box article a few times, I have some questions. So is the RDP filter box different from a ordinary sump with macroalgae and a night light? Or is the RDP only used at night when the main tank's light are off? Or can I run the overflow to the RDP filter box all the time, and only turn the light over it when I turn off the main tank's light?

So this is what I'm thinking:

Overflow from main tank --> prefilter --> RDP filter sump --> protein skimmer --> pumped back to tank.

This seems to me that I just have to convert my existing sump into a RDP box by adding macroalgae and a egg crate into my existing sump and throw a light on top. Or do I have to get a separate tank for the RDP? ??? ???

I have just purchased a new 50 gallon tank and want to put LS/LR into the main tank, and use a ~ 10-20 gal sump coupled with a good protein skimmer. ;D ;D ;D Any advice would be greatly appreciated. :thumbsup:

 

I can't help thinking of the 'night light' I had when I was a kid. You don't mean that, right?  ;D

No it is not different except for the light cycle. Yes, the lights are turned on the refugium essentially after the main lights go out. One guy I met who runs RDP, reverse daylight photosynthesis, said to have the light cycles overlap by an hour. So the refugium lights would go on an hour before the main ones go out and turn off an hour after the main ones come on. This helps prevent the swings in PH that can occur.

Yes, the water should be going through the refugium at all times. A slow flow gets maximum results. More effecient. But, since you plan to do it in your main sump, you won't have that control. It will still work, but be a little less effective.

Bingo.

You don't have to. But the separate tank will allow you to control flow rate and give you more room in your main sump for other hardware.

See the 'refugiums' section for more details on setup, types of caulerpa to use, etc...

You are on the right track. Good luck Jimbo!   wahoo!!!!!

 

By the way Jimbo,

I am not trying to push you towards one setup over the next. My understanding is that there are pros and cons of each. Read the refugiums section and figure out what works best for you.

 

Hey,

Thanks for the reply...

After looking at my tank, my setup actually goes like this...

Overflow --> prefilter --> protein skimmer --> RDP box --> pump back to tank.

Would this be ok if I have the protein skimmer step comes before the RDP box??? I ask this because I have one of those Seaclear system with built in filtration in the back...and that is the schematic of the system. Unless I do some drilling and modifications (sump+additional skimmer), does this mean I can't use a RDP setup. Thanks again.

My RDP box is basically some bio-balls (not refugium) and I would have to add an additional light at night (not night ligt for kiddies hehe) over that section. Is this ok???

 

Yeah that will work, maybe even better Jimbo.

The skimmer will get the less polished water and the caulerpa will try to mop up the rest. I like it.

Not sure what you are saying about those bio-balls though. Are you removing them completely or putting the caulerpa over them? If you are leaving them, are they completely submerged?

By the way, if you take a second to become a member here, the forum will remember you (you won't have to log in) and you can be notified via email when somebody responds to your post. Hint, hint, know what I mean?    ;D

 

Thanks Matt. I was thinking instead of putting the egg crate, I'll just use bio-balls with macroalgae. The section with the bio-balls will be half submerged. It's half submerged because the tank's filtration system is designed to overflow into a tray with holes (that is sitting above the bio-ball section) and the water drips down onto the bio-ball section.

I will need to get a new light for that section then. Will an actinic light do??? I appreciate all your help. And what kind of macroalgae should I grow??? I'm not familiar with macroalgae...you mentioned calperas??? Can I get that in my local fish store or where do I order it??? Or does it come naturally to a tank??? Thanks.

BTW, just to update you on my progress, I'm kind of short on cash right now (on budget) and I decided to add 2 compact flash fluorescents to my lighting. I sawed my lighting canopy and added 2 compact flash fluorescents (65w each) from home depot to my canopy. Cost me about $50 total. I hope to grow corals and soft corals. I'm working on the electrical connections right now. Wish me luck!!! ;D

 

Jimbo thanks for joining the forum, I appreciate it. It is new and I am not advertising yet, so everyone counts.

Let's take a look at your filter:




This is a SeaClear System II. This is what you have right?
I don't see a protein skimmer, was that an option, or did you put one in your self?

Anyway, looking at this setup, I assume that you were thinking of pulling some balls out and putting the caulerpa on top.

I don't think this is a good idea. Unless you have a sand bed in the main tank along with somewhere in the neighborhood of 80-100 pounds of quality live rock in the tank, you are going to need all those bio-balls.

Lets say you did have the rock/sand and a good skimmer. I would then remove all the balls and put the caulerpa in there. You wouldn't have a very big refugium, but it would help I guess. The denitrifying bacteria that grow on some of those balls do not like light. So I would go one route or the other here. Going half way, you will have a little benefit from each but you are not getting the biggest return on the deal. Plus removing caulerpa that attaches to the bio-balls would be a pain in the ass.

hth

 

Wow, nice picture of my tank!!! Hehe. The protein skimmer goes on #3 section of the picture, it's an added accessory which I bought. Yeah, I don't really understand the bio-balls... I know I will have to wait to get the bacteria to grow on them, but I don't know what will be growing. So...

I just went to home depot, and I bought a plastic egg crate thingy (gutter cover) and some pvc pipes. I'm going to stack the egg crate with the pvc (in the bio ball section, I'm going to take out the bio-balls). I'm going to put some good macroalgae in that section. Where do I get Caulerpa????

What do you think?

 

Well the bio-balls are just an excellent harbor for the bacteria due to their large surface area. Having wet and dry areas and some submerged balls, there will be aerobic nitrifying bacteria and some denitrying anerobic bacteria there. The former takes in the ammonia which is highly toxic to fish and gives off the less toxic nitrite which is absorbed by nitrobacter bacteria and converted to even less toxic nitrate. The anerobic bacteria take care of the nitrate and convert it back to nitrogen.

It is important to have a nice sand bed in your tank because this will eventually have a lot of the anerobic bacteria in it that will help keep the nitrates down. Off the top of my head, I think >20ppm of nitrate starts becoming pretty toxic to fish. Of course regular small water changes help keep it down too.

Anyway, enough of the biology lesson, bottom line is, like I said earlier in this thread, if you don't have adequate rock/sand I would not remove those balls. If your rock is extremely pourous and both it and the sand are top quality, you can get away with a little less than I recommended.

The caulerpa, which you can get from your local fish stores, is excellent at absorbing phosphates and nitrates, but I don't think the space you have available is adequate to have enough caulerpa to compensate for the lack of bio-balls should you not have enough rock and sand.

That is the best advise I could give. I wouldn't get rid of something because I don't understand it, you know what I mean?

Hope that helps Jimbo. Keep me posted. :thumbsup:

 

Yes, that is very helpful. I guess I will just have to try different setup and see what I get. For now, I guess I'm going to use the LR/LS and bio-balls with phosphate remover granules and activated carbon bags. I did read somewhere that the bio-balls actually increase nitrate in the tank...?? Haha...so many different point of views

I've finished modifying my tank, and is now ready to insert live sand, rock and water!!! ;D Very cool!!!

I'm going with DSB 2+ inches because personally, I read it somewhere...in FAMA I think...that DSB is just as good as Jaubert method. Matt, I also read that putting some LR directly over LS is actually a good idea because it give an undisturbed area for the nitrate to be broken down in a DSB setup. (instead of putting as little surface area of the rock on the sand as some suggest).

I think I'll borrow my friend's digital camera...and try to snap up a few pictures of my setup... hehe 8) oh_yeah 8)