Overflows and return pumps, FW...    8/8/07
Hello Crew!
<Danny>
I have an 86 gallon FW heavily planted tank with a 20 gallon sump (still under construction, the sump not the tank), and an external, HOB overflow box. I am using an Eheim 1261 return pump with 3/4'' plumbing to the tank, and I mistakenly used 1" drain plumbing from the overflow to the sump. The pump, needless to say, overwhelms my overflow. To rectify this, I was thinking of adding a ball valve to the return to throttle back the return pump.
<Mmm, perhaps better to divert this excess flow back to/through the sump... via a Tee and a valve...>
But, I want to upgrade the drain.
Should I go with 1-1/4" drain or 1-1/2" drain?
<The bigger the better... for flow, as well as noise reduction. But... better still would/will be to add yet another overflow box if going that route>
I don't really want to throttle back the pump, if I don't have to. I want to avoid overrunning the overflow at all costs. The overflow has a 1-1/4" bulkhead, but it also has a 1" pipe for holding the pre-filter. It seems that no matter what size drain I use, the 1" pipe is going to be my bottle neck.
<Yes>
I have heard of drilling holes in the 1" pipe to alleviate the bottleneck there, but I think it will introduce a lot of noise. Any suggestions? Is there any downside to restricting the return pump (aside from the obvious loss of gph?)?
Thanks,
Danny
<Please read here: http://www.wetwebmedia.com/marsetupindex2.htm
the yellow tray... re plumbing... The same input applies here to all tank types. Cheers, Bob Fenner>

Question about sand and filter impellers – 06/11/07
Hello everyone,
<Hello.>
I have a question about sand's effect on hang-on filters. I added some extremely, extremely fine sand to my tank (it's by Zoo-Med, called "Repti-sand"). It's made of quartz and is very, very fine and light, so much that it took about 2 days until the water was clear after I added it to the existing tank. Really, it's more like dust than sand. Anyway, I have four emerald Cory's in there now, and they love scooting around in it and it's very soft so it's easy on their bodies. It also hasn't affected my pH. I've had it like that for about a week and a half, and then last night the filter started making some grinding noises, so I pulled it out, rinsed it out (some sand came out) and tried to get it to work a few times. Then I looked online and read about impellers, and I saw that the impeller was broken (its blades go around and around). Do you think it's the sand that caused it, or my jiggling it around and taking it apart a few times trying to get it to work, perhaps not being gentle enough, that did it? That one was a Penguin Bio-wheel, and I got a new one today, an Aqua Clear with the different style of filtration. This one's making kind of a gritty noise as well, and I'm afraid it will break, too. Is this a common problem? Do you think I should get rid of the sand, or at least get some heavier sand that isn't so easily disturbed and sucked up into the filter? I do want to keep some sort of sand because I want to get kuhli loaches later on.
<Sand can damage the impellers of pumps. It isn't common though. I use silica sand in all my aquaria, and while sand sometimes gets stuck inside the filter canister, it doesn't seem to do any harm. But your own mileage may vary! Silica sand in particular is quite heavy and settles very quickly. The only time it gets into the water column (and thus into the filter) is when a big catfish decides to swish into the sand and dig herself a burrow. Small things, like Corydoras, simply don't push the sand far enough off the substrate to cause problems. Now, if sand gets inside the impeller, it can quite possibly cause some rattling noise. In the long term, anything that clogs filter media forces the impeller to work harder, and puts all its components under more stress. You probably want to make sure the filter inlet is far enough above the substrate that the fish can't swoosh the sand into the filter. Adding a decent pre-filter layer to your filter system (such as filter floss) is also a good idea. My gut feeling is that while silica sand has been used for many years by many aquarists without problems, finer sands like your Repti-sand might be just a bit too fine for safe use.>
Thanks for any and all help you can offer! I really appreciate it!
Allison Evans
<Hope this helps. I'm a BIG fan of sand in aquaria, and agree with you that loaches and catfish really benefit from its use. But it does need to be handled properly. Cheers, Neale>

pH and water flow  5/17/07
Crew,
<<Hi, Erik. Tom with you.>>
Great site, thank-you.
<<Thanks, Erik. Glad to hear we’ve been helpful so far.>>
I have a 30 gallon tank with Eco-Complete as substrate and nothing else in it. I use RO/DI water. My Pinpoint pH monitor reads the pH as 7.2 and up with the Whisper 40 running (only has carbon in it) and reads 6.75 and lower with the filter off and not flowing at all. Why?
<<Well, now both of us have an issue to deal with. Your issue is that pH monitors don’t work well in purified (RO/DI) water. Mine is trying to explain, in simple (?) terms, why they don’t. First, and not surprisingly, RO/DI water has very little in the way of buffering capacity which means that pH can change quite readily, up or down. Simple enough. Second, commonly our pH is affected by the absorption of CO2 from the atmosphere. This is why you can expect pH to typically decrease over time since dissolved CO2 in the tank lowers pH. How quickly this takes place depends on a wide number of factors but, once again, this can depend, in part, on the buffering capacity of the water. In our homes, CO2 levels can be, and typically are, higher than outdoors yielding a higher concentration of the compound in the air and, therefore, greater opportunity for our tanks to absorb it. (RO/DI water generally runs in the pH range of about 5-7 depending substantially on the level of dissolved CO2.) Third, CO2 is “driven” out of the water by agitation such as what you might create with airstones, UGF’s, HOB filters, etc. Though this doesn’t even scratch the surface of a highly complex topic, I believe that what you’re seeing is the absorption/dissolution of CO2 in your tank caused by calm periods (filter off) resulting in increased CO2 absorption (lower pH) followed by active periods (filter on) resulting in decreased CO2 (higher pH).>>
Also, the readings on the pinpoint monitor fluctuate a tenth of a point constantly, it is never pegged. I know constant pH is better than a specific reading and I can't get the pH to stay at one reading even in this small tank.
<<The greater the precision of the instrument, the more likely it will be to show variances, Erik. You might think of it like the “refresh rate” of your computer monitor. The higher the refresh rate, the more screen “flicker” you’ll observe. Your Pinpoint monitor is constantly refreshing its readings. In conjunction with what I’ve already discussed, I’d be very surprised if it weren’t constantly fluctuating. A very nice piece of gear but it has drawbacks in this particular set of circumstances.>>
Respectfully,
Erik
<<Hopefully this will shed a little light on your situation, Erik. Best regards. Tom>>

Automatic leak detector/ water valve shutoff system?    5/2/06
Hi,
     I have a FW African 120G plexi tank that is plumbed through the bottom through a double size Lifegard set (UV, mech, chem, and heater modules) then
back up through spray bar towers in the corners, the tank is visible on three sides so it was important for me to have as little filtration/equipment in
the way as possible. I have three drains that T into one 1" pvc line, and the strainers are only perhaps 1.5 inches above the sand. Looks great, works
great, but what if there is a leak!?!?
<... water on the floor, possibly drained down to their level>
It has been up over 6 months or so and have had little trouble, but it is always in the back of my mind.
Ideally I would rig a leak detector up to a relay that upon detection of leak, it closes the in/out ball valves and turns off the UV and pump.
<There are such alarm devices on the market>
      I have the leak detector circuit and am fairly competent on wiring all the relays, but what is holding me back are the solenoid valves.
<Where would you install these that would help?>
I thought that I would be able to use a sprinkler valve as they are cheap and pvc, but to throw the ol monkey wrench in my plans, it has to have a minimum of 15psi
to operate correctly. I am running 3-5 tops. Does anyone know of a different type of valve that would fit the bill?
<None that I would use>
I know I can put a check valve on the return line, which I should have done in the first place, but I still would
like at least one that would close the system down if I were to spring a leak.
     In the meantime I have plans to raise the drains up so if it does happen, at least my fish may have enough water to survive the event, and
also I think I may drill a drain through the floor (under the tank in the cabinet) as to not flood my room. Any advice? thanks!
<Mmm, I would not worry here. The likelihood of a disaster is likely very small... Next time/tank, either drill through the back or run the (return) lines over the top, the drains through the tower/s. Bob Fenner>

Too much filtering or water movement How much is too much? - 20/1/05
I was wondering what would be considered too much water movement. I have a 75 gallon tank and one Fluval
405. I wanted to put in a second Fluval 405 to make sure the tank stays nice and clean. But then I was
worried about the problem of too much water movement. Right now the fish in the tank don't seem to have any
problems with the one filter. What do you think?
<Depends on the fish (and, more importantly, corals. However, in general, fish can withstand - and sometimes prefer - far higher currents than we provide. Ever swum in the ocean? Or a fast flowing river? If I am right in thinking that a 405 provides a max. flow of around 350gph, then two such filters would be perfectly suited for freshwater.... I would be looking for more flow for most marine tanks. Best regards, John>
Thanks,
Rusty