Filtration Capacity...This is ONLY a Test... - Page 4 - Filtration

niko · 08-19-2012, 07:37 PM

You know, about this laminar flow thing... I now have observed 2 tanks that had amazing flow rate and pattern from the cheapest HOB filter you can think of. And the water stayed crystal clear. One of the tanks I setup for a friend of mine who had never had an aquarium. He had 2 gold fish and the tank was 10 gallons. For a year this tank stayed crystal clear. No plants, no light but still - tank looked setup 5 min ago a year later.

The second tank I'm still playing with but I can see the big difference in it after properly placing the filter. The cheapest HOB works very, very, very well IF placed on the side of the tank. The tank is 29 gallons, the filter is a stupid small size HOB. It discharges an almost horizontal sheet of water close to the surface of the water. I guess that is as close to laminar as we can engineer it. The inflow is a few inches above the gravel (just like ADA's). The tank cleared up to crystal clear state within 30 min after I moved the filter. It used to hang on the back of the tank, debries where settling everywhere, and algae ate me alive despite 10% daily water changes (yes, daily) and feeding the 3 small fish once every 3 days. No plants, one 15 watt bulb and I was growigh algae at Olympic level speed. I blame all of that to the flow pattern AND the lack of biofiltration.

The problem with that filter is that has no volume to accomodate any reasonable amount of biomedia. For a long time now I've been thinking of a huge volume HOB filter. I've seen only 1 Japanese HOB filter like that. Basically and HOB with a huge box, that's all.

Today I got an Eheim canister for this 29 gallon tank and will fill it with 100% lava rock. I will still keep the cheapo HOB - the thing really moves the water in a beautiful U-shaped pattern when placed on the side of the tank.

So how does the water in your small experimental tank look now after almost a month of no care?

Tex Gal · 08-19-2012, 07:55 PM

I'm a little confused, Mudboots. Isn't the 9w less light than the Darth Vader light? SO with just the light change - filter staying the same- you are now getting algae?

Michael · 08-20-2012, 05:56 AM

Niko, after your famous "excited" thread, I moved all my HOB filters but one to the side position, with the outflow closest to the front glass. I think this is absolutely the best way way to use them.

The only tank that isn't arranged that way is very visible from the sides and I really do not want to see the filter there. But I am thinking about changing it anyway!

mudboots · 08-20-2012, 06:59 AM

Niko, TexGal et al...

So far the water is still very nice. There is still a good amount of organic mess from the dead plants I had in there, but not much left. I do a 50% water change every once in a while, less than weekely.

The only issue is the algae mess, which TexGal asked about. The algae is that brown dusty stuff, so I guess diatoms? Not really sure. Maybe the extra light gave the plants enough juice to process all the excess nutrients I pumped in there via fish food and dead plants, adn the organic decomp provided CO2 like a med-high tech setup. Then with the sudden drop in light from 20 watts to 9 watts there was a sudden burst in available nutrients that are not being used by the plants (not enough PAR to keep them moving the cycle around). So I may just need to put the bright lights back on, or just leave it alone and let time take care of the excess, which shouldn't be too long from now since I don't overfeed anymore, and the organics are starting to go away.

Any thoughts on that from anyone???

One thing that is really cool is the flow pattern test. When the water exits from the old HOB chasis it seems to be high flow, but when I set the outlet hose in the water and let it come off the left side of the glass (near the corner actually) the same flow rate seems nearly invisible. And it's actually slight higher flow rate because I've dropped the head by two inches. It's like I could double the flow rate and not cause a mess. The water surface doesn't even shimmer with movement. I can't test this though because my overflow is too small to handle more flow, and it'd look pretty sick to have a 1" overflow pipe in a tank that small.

Silvering · 08-20-2012, 09:03 AM

I have a 20 long with an HOB filled with biomedia mounted on the side, too. I can't imagine what a mess it would be to mount a single HOB on the back of a 20L, probably have stagnant spots everywhere! The trouble is, none of the commercial lids will fit if you mount the filter on the side. LOL Got some acrylic to make my own lid instead. :3

No useful comment to make about the lighting, I have no idea

niko · 08-20-2012, 01:13 PM

About the placing of the HOB: The tank in which I moved the HOB on the side started with the HOB hung on the back and to the left. The entire right side was stagnant and that's where the algae grew even with my daily 10% water changes. Where there was water movement the algae was much less - maybe 25% of the algae mass on the right.

Then one day I moved the HOB to the middle. It hung on the back glass and was dead center. Within 2 days the entire tank got covered with algae. Some kind of dark green, almost grey kind. And slimy. It looked like a layer of algae mixed with mulm. It covered everything. It could be that since the HOB does not have enough area for biofiltration my biofilter was the actual tank. I don't know. 1/8" thick slimy layer over everything is a pretty rare and ugly sight. At that point I just abandoned the tank.

It all changed when about a month later I moved the HOB to the side glass and noticed the huge flow rate U-shaped flow.

mudboots · 08-20-2012, 05:29 PM

I'm about to post another video example that shows a little better what the Laminar looks like (just click the pic and it is a link to a photobucket video), plus is a better shot since the water cleared up following the disturbance.

For clarification, on flow rate the pump is rated at 150 or whatever, I may have noted that number in this thread at the beginning, and at the outlet height the rate is supposed to be in the upper 40's in gph, which is why I state between 40-50gph. If you look at the surface from inside the tank during the 2 minute or less video you can see the whole surface slowly migrating to the overflow as a solid mass. The water underneath moves with it, but not excepting the obvious laws of physics. I didn't vid-shoot the turbulent again because I think we all know what that looks like; the typical jet-steam that blows the plants sideways et cetera when the flow rate is between 16-20x tank volume (this tank only holds about 2.5 gallons).

Michael · 08-20-2012, 06:08 PM

Photobucket will only allow me to see a few seconds, then closes the video and demands that I register. Since internet coercion is against my personal moral code, I'll have to take your word for it.

mudboots · 08-20-2012, 06:41 PM

Well I don't like forced registrations either...you don't happen to know of another way I can stick video clips on here by chance? The only reason I have photobucket is because I had an account a LONG time ago and it seemed easy to navigate.

Anyway, it's pretty cool to watch, especially when I remove the screen thing off the top of the overflow and stir a bunch of stuff around.

kwc1974 · 08-21-2012, 01:29 PM

Mudboots

The problem I an starting to see in my tank that has the laminar flow is this. Without any turbulent flow, by CO2 diffusion is not as reliable since we often use the turbulent flow to move the CO2 around the tank. Without this mix, even in a small tank (60P) I had issues. The most obvious fix is to reactor inject my CO2.

Beyond that water stays clean. Flow is very slow to the point that very delicate plants don;t move at all. Funny how a simple part change has a dramatic outcome like this. (to catch people up on a conversation mudboots and I had I am using the ADA metal pipes I started with the metal jet pipe and the tank was too turbulent, and with the standard metal outflow pipe no turbulence)