So back to plumbing I decided not to dissassemble everything for the 3rd time and added several 45 degrees elbows to direct on tube towards the bubble tower and another one to the back then along the side of the sump to the bubble trap and it finally worked. Skimmer did not fit inside the skimmer section so I put it inthe return section receiving water and outputting it in the skimmer section so only difference was a bit less space in the return section which is big enough anyway. I also believe will have space to put my Turbofloater 750 SL (that I'm musing in my 8o gallons) in the skimmers section. that skimmer should be used submerged anyway. so in the end I have this plumbing.
I did overtighten the bulkheads a bit in the end so that they would stop going loose each time I hit a tube and caused minor rotation. I did check the plumbing and the tanks for 2-3 days to make sure nothing was leaking. the waterflow was very noisy however I didn't pay any attention to that as I always hear that the tubes need to slime and saltwater is more heavy and causes less noise...
So at that stage I had the plumbing from the tank to the sump done and tested, also the 24 G frag tank that I bult myself was also connected to the skimmer section. I was unsure if I will supply water to it from the tank drain or from a pump in the sump and then have waer flow back by gravity. then I decided to go with supply from a pump. to my surprise the two 1/2 inch holes in it connected to a 1/2 inch hole in the skimmer section, were not able to drain back the flow from a 300 L/H 80G/H small pump. and in the end water was going to overflow. I tried making it higher by disassembling the connection and adding one foam sheet under it still it didn't make much more difference. redid the connection and rose it two foam sheets now it was good and able to handle the flow up to 250 GPH. but that made me loose around 5 inches fromt eh height as water would keep at the same level of the water in the skimmer section.
Finally i understood that the problem was a 2 part problem:
the valves I was using to be able to shut the water off were reducing the flow to 1/4 inch so i took them out.
in the end I had only one 1/2 inch hole inthe skimmer section getting the water back and it seems not to be able to handle this much flow. I had made two holes for return in the frag tank and though that one would act as backup in case the other was blocked but had only one hole in the skimmer section. so I cancelled the idea of having a spare hole in the skimmer section to connect to a future Calcim reactor and used the upper hole that you see in teh picture as a 2nd drain. water drains from one lower hole in the frag tank to one lower hole in the skimmer section of the sump and from a second hole down in the frag tanl to an HIGH hole in the skimmer section. it does not have as much presure as the low hole drain but does a good job... If I was doing it again I would have gone for 2 holes high in both tanks??? any suggestions or explanation here would be appreciated.
With this setup I was able to only have one additional foam sheet under the tank. water would rise 1inch max if I have 250 Gph pump. still I will only be using a 500 L/H 135 Gph to be on the safe side if any snail or anyother thing blocks the return. I could always add to the circulation by adding a pump to the frag tank as it will not be seen anyway.
so the plumbing for the tank to the sump was done 3 times and the connection from the sump to the frag tank more than 7 times and this was very difficult as I had limited space so no matter how soft the tubing is the tub has t be exactly the same length to avoid pressure on bulkheads and avoid having the tube get compressed and close. PVS tubing was out of question as space was too limited.
in the end it is working and it seems water level is always at a safe margin. do yo uthing this will cause a risk in the future? in this case should I discard the idea of the frag tank? the main interest is that it acts as more space for teh water to rise when the pump is shot and also adds water volume in addition to be a good place for introducing corals... As I said any input is critical as I hate to have to uninstall it when the wood covers are here.
I decide to get some sand and got 45 pounds of fine coral sand rinsed it 2-3 times and added it to the frag tank it gave me around 3 inches deapth (tank is 20x18x20). I topped it with 3-4 cups of live sand from my tank and got few LR pieces that were in my ld tank refugium with 2 gallons of old tank water and added them put everything in the frag tank and ran the lower part of the system: water flowing from refugium on left to frag tank and getting back by gravity from frag tank to skimmer section-return sectin and then to refugium. I also ran my skimmer as the water loowed a bit cloudy. amazingly after one day I had lots of skimmate smelling ilke sand. water was a bit cleaner but not crystal clear. following day I had 1/4 cup of very nasty smelling skimmate. and that's only from some rocks and water from old tank that was transported in less than 30 min. I wonder how bad it'll be when I move all my sand bed. Cause for running the system is that I have now some place to put my corals (in addition to old tank refugium) while transporting all my stuff. I will have till then a cycled frag tank that can handle some corals and fish and maybe boost the filtration of the main tank when started.
