suphew

Go with the baking soda, then you have control over your Kh. I'm not sure how adding SEA shells to a fresh water tank is more natural. With Baking soda you get just the chemical you need, with sea shell, you get the same chemical plus every thing else that went into making the shell, calcium, magnesium, phosphate etc etc.

This is a common issue (or non-issue) for marine tanks as most have sumps. The solution is to drill an anti-syphon hole on the return just below the water line. Then the outlet of the return can be as low in the tank as you want it. When you pump stops the tank will drain a little, till it gets to the anti-syphon hole, then stop, you just have to make sure your sump has enough extra space in it to hold this water.

If your tank setup is okay for corals you don't need to transfer them slowly, you can move the whole lot at once. To check the reef compatibility of your fish just Google them, most identification sites include compatibility. Here's a good starting point http://www.pbase.com/clippo/marine_fish

Apologies David.

No I wouldn't accept something that was obviously incorrect as you have admitted. Your calculations are now based on less that 10% of the tank being supported, this isn't "simply a place to start- assumptions to get things going" it is (IMO) an very low figure to use, but I am happy to be corrected if this isn't the case. If I hadn't posted the figure of 900kg per square millimeter would still be standing. I'm sorry that I incorrectly took it personally and accept that this wasn't your intention. Statements like the above made me feel like it was personal.

Sorry but a statement like "I give up, you seem know everything" felt pretty personal and abusive, if that wasn't the case, I take back what I said. Of course I said that before you edited your post. BTW I'm a computer engineer, and qualified electronic's engineer, so, yeah have done a little maths. Have also been keeping fish for round 30 years.

When did this become personal and abusive?? :evil: I'm quite happy for some one to show me if I have made an error and will learn from it. Everything I have said is based on what I have seen working with my own eyes.

To weld steel flat is easy, you attached it firmly to a solid flat surface before you weld it. Pretty common practice as I understood it.

Ok, its big, made of glass and has been sitting in my lounge for a few years..... thats about all the back up I feel that I need. There are so many guesses, assumptions, and holes in this calculation I'm not even going to start on it. As I said before "But when it comes down to it, it's your peace of mind. I just think your panicking for no reason and will end up spending money you didn't need to.". Go with the the benchtop or 30mm marine ply, a hundred or two is often worth peace of mind.

BTW if you actually are that worried about this, buy a kitchen bench top, which will be dead flat and very unlikely to bend. A secondhand one will do, paint the bottom with oil based paint to seal it, and to make double sure screw some box section to the bottom of it. Sit this on your stand and pack out between the stand and the bench top. But first make sure your stand legs are all firmly attached (bolted) down to the concrete or the stand might bend once the weight goes on.

To have made this calculation you would have needed to know what the area of the high points was, which you dont know, so this is a pure guess. Secondly, (correct me if I'm wrong, I'm not a mathematician) but to get 900kg psmm wouldn't you need 900kg?? The tank holds round 600l of water if completely full to the brim so 600kg of water plus glass plus gravel etc, I think you would be lucky to get to 900kg total. So to have 900kg psmm would put the whole weight on 1 square millimeter. If it was going to break why would it wait till you had added your fish, The most stress the glass is going to have is when the weight is changing, i.e. when you are filling the tank. Wood is never going to be flatter than steel. Plus the joints can move, wood can bow and twist over time, I would think it would be more of a risk than the steel one. (BTW my stand is made from wood). There are likely hundreds of tanks in New Zealand as large if not larger, most of the owners wont have even checked to see how twisted their stand were. I have personally helped moved 3 tanks larger (not including my own), one 4 times the volume of yours and I know for a fact the owners only properly checked the stands after they were filled for testing. And this was for level not twist. But when it comes down to it, it's your peace of mind. I just think your panicking for no reason and will end up spending money you didn't need to.

ok 1570mm - 1500mm = 70mm, or how much longer my tank is. :roll: Silliness aside there are three points really 1) my tank, non-flat stand (proven by poly moving in middle of tank when full), two years, no problems. "Never the real world get in the way of a good calculation" 2) Logic, for the tank to break from twisting, it has to twist. This can only happen if a) the silicone comes loose at the joints so the bottom can twist separately from the sides. Or b) the side glass bends along its axis. If a) happens, its because of a very badly made tank, and would likely have come apart anyway, if b) happens I'll eat my hat. 3) whats the worst that can happen?? It's in a garage, the bottom glass breaks, some water spills, its costs $100 for a new piece of glass and I have to eat my hat.

Put it on and fill it up, it will be fine. My tank is longer and my stand was at least as bowed, I can move the poly up and down in the middle of my tank, if it wasn't one sheet I would be able to slide it out. It's been like this for two years. I also have five holes drilled (~40mm) in the bottom of my tank making it even weaker than yours. Most people grossly underestimate how strong glass is when make into a cube like a tank, for the bottom of the tank to twist and break either the silicon would have to come undone or you would have to bend the side glass down its axis, neither is likely to happen. The reason tanks break is because of single high pressure points, the poly takes care of this.

I think cyano is just one of those stages tanks go through, some people are just lucky and it is not very noticeable or doesn't hit them. Things can help clear it, water movement, skimming, PO4 removal, improving light, turning off lights, vodka, etc etc. But for most people they try lots of different things then suddenly it just goes, often despite some of the things they have done to their tanks! The advice I'd give you is to replace your light bulbs if they are old, replace your skimmer if it is crap, increase your flow (by my calculations (at ~11000lph or about 27 x tank) you are sitting near the bottom end even including the 6045), and look at how much you feed and maybe feed less (having fat fish isn't being kind to them or the tank).

Wow thats a big statement. I wonder what the likes of Boomer and Steve West, who post on some other NZ Marine web sites would feel about that.

What rockerpeller has drawn is the way to go, the only thing to add is a reducer on the bottom, this give it some back pressure. Once it is set up you drill a small hole in the cap on the top and keep making it larger until it is tuned correctly, the instructions are on the durso web site.

You wont need the baffles in the sump, they are only needed for salt water which holds bubbles, the baffles drive the bubbles to the surface. You just need to arrange a divider(s) to hold your bio media in place and force the water to go through it rather then just flow over the top. Get a good return pump, an ehiem 1260 or 1262 would be good, you want a good, quite reliable pump, and remember how much money you will be saving on filters, Its worth spending a hundred or two on a desent pump. PVC is usually the best, but is it the best for you?? Well that depends on you. Personally I only use PVC pressure plumbing, flexy plumbing MIGHT come apart, it MIGHT leak, so I dont use it. But PVC costs a lot more and is a lot harder to plumb and some people have no problems with flexible plumbing Best media? if your going to the trouble of running a sump you want fill it with media, filter wool is most just mechanical filter, you should just use it as the first (and maybe) last stage and should replace/clean it often. You main filter should be bioballs, or cermic filter ball etc etc what ever you can get cheap all you need is the most surface area you can get, pegs, chopped up straws, just about anything will do. For overflows read up on the durso stand pipes, not the only option but the most common and IMHO the best. http://www.dursostandpipes.com/

I had one done, it cost about $150 all up (filled) from memory, you need to get it done professionally otherwise it wont be certified and you wont be able to get it filled. If you can get a steel one, they last longer and are more likely to pass the cert, but are harder to find. The ali ones crack around the neck. But in saying that mine is ali. Most of the cost is the valve, the cert was about $30 and about $25 to fill. I got mine from a metal recycler, he was only interested in the metal value so agreed to swap cylinders until I got one that passed

Clowns and seahorses will be a problem together, youll find it very difficult to feed the seahorses because the clowns will eat everything before they get a chance. Clams and Anenemies needs as good water quality/parameters and light as hard corals. If you are planning a softy only tank because you like them thats all good and well, but don't think you will be able to get away with less light, flow, calcium, etc etc. Anenomies are as difficult (and more so in some cases) as hard corals and clams have large calcium requirements for growing their shells.

Have a read of Carols pond build tread, she had loads of problems doing this.

And dont forget that the bottom piece of glass will need to be bigger than the sides. The sides need to sit on top of the bottom

All types of stainless steel will rust given enough time in salt water. This is why temp probes etc use titanium. I suggest you use glued pressure plumbing. If it's leaking now, at very least you will get salt creep in the longer term, at worst your fittings will come apart usually in the middle of the night or while your on holiday.

Usually the first spong is a machanical filter to stop the larger bits of rubbish getting to your noodles or other media and blocking up the fine pores where the bacterial live

The order of the media in the filter shouldn't cause this problem. Plus I would expect that if it was just dirt in the gravel it would have settled by now or at least you should be able to see it getting clearer. My guess is that its a bacteria bloom, I'd leave it for a couple of days and see what happens. If its dirt your filter will get all clogged up with silt and your tank should be clearing up. If its a bacterial bloom your filter wont silt up but it will still clear given a bit more time.

Think it would be better flowing the other way, you want the water from your overflow to hit the skimmer first, ideally gravity feeding directly into it. Personally I would also dump the middle section or just have rock in it, using micro algae for nutriant remove doesn't work very well and can cause problems, like releasing toxins, and getting into your display.